阅读说明：本技术 使用磁流体轴承的转子多源约束防爆电机 (Rotor multi-source constraint explosion-proof motor using magnetic fluid bearing ) 是由 何凡 于 2020-02-05 设计创作，主要内容包括：本发明公开了一种使用磁流体轴承的转子多源约束防爆电机,铁芯置于机壳内,铁芯中央连接主轴,主轴从机壳端部伸出电机外,防爆电机还包括磁流体轴承,机壳被主轴穿过的位置处设置安装槽,磁流体轴承设置在安装槽内。磁流体轴承包括单体轴瓦、轴套、端盖和磁流体,单体轴瓦包括永磁体、隔离块、座环；轴套套设在主轴上且与主轴传动连接,轴套与主轴的圆柱接触面上设置密封圈；座环安装在安装槽内,座环外圈与安装槽内圆柱面接触,永磁体外缘处嵌合在座环内圈中,永磁体内缘处为环状,相邻永磁体的内缘之间垫入隔离块,永磁体和隔离块在内缘处构成完整圆柱内圈并与轴套外表面抵触,单体轴瓦内圈与轴套外表面之间注入磁流体。(The invention discloses a rotor multi-source constraint explosion-proof motor using a magnetofluid bearing, wherein an iron core is arranged in a casing, the center of the iron core is connected with a main shaft, the main shaft extends out of the motor from the end part of the casing, the explosion-proof motor also comprises the magnetofluid bearing, a mounting groove is arranged at the position of the casing, which is penetrated by the main shaft, and the magnetofluid bearing is arranged in the mounting groove. The magnetic fluid bearing comprises a single bearing bush, a shaft sleeve, an end cover and a magnetic fluid, wherein the single bearing bush comprises a permanent magnet, an isolation block and a seat ring; the shaft sleeve is sleeved on the main shaft and is in transmission connection with the main shaft, and a sealing ring is arranged on the cylindrical contact surface of the shaft sleeve and the main shaft; the seat ring is arranged in the mounting groove, the outer ring of the seat ring is in contact with the inner cylindrical surface of the mounting groove, the outer edge of the permanent magnet is embedded in the inner ring of the seat ring, the inner edge of the permanent magnet is annular, the spacing block is filled between the inner edges of the adjacent permanent magnets, the permanent magnets and the spacing block form a complete cylindrical inner ring at the inner edges and are abutted against the outer surface of the shaft sleeve, and magnetic fluid is injected between the inner ring of the single bearing bush and the outer surface of the shaft sleeve.)

1. The utility model provides an use rotor multisource restraint explosion-proof machine of magnetic fluid bearing, includes iron core (1), main shaft (2) and casing (4), in casing (4) were arranged in iron core (1), iron core (1) central authorities connect main shaft (2), main shaft (2) are outside the motor is stretched out from casing (4) tip, its characterized in that: the explosion-proof motor further comprises a magnetic fluid bearing (3), a mounting groove (41) is formed in the position, through which the main shaft (2) penetrates, of the housing (4), and the magnetic fluid bearing (3) is arranged in the mounting groove (41);

the magnetic fluid bearing (3) comprises a single bearing bush (31), a shaft sleeve (33), an end cover (34) and a magnetic fluid (35), wherein the single bearing bush (31) comprises a permanent magnet (311), an isolation block (312) and a seat ring (313); the shaft sleeve (33) is sleeved on the main shaft (2) and is in transmission connection with the main shaft (2), and a sealing ring is arranged on the cylindrical contact surface of the shaft sleeve (33) and the main shaft (2); the seat ring (313) is arranged in the mounting groove (41), the outer ring of the seat ring (313) is in contact with the inner cylindrical surface of the mounting groove (41), the outer edge of the permanent magnet (311) is embedded in the inner ring of the seat ring (313), the inner edge of the permanent magnet (311) is annular, a spacer block (312) is arranged between the inner edges of the adjacent permanent magnets (311), the permanent magnet (311) and the spacer block (312) form a complete cylindrical inner ring at the inner edge and are abutted against the outer surface of the shaft sleeve (33), and a magnetic fluid (35) is injected between the inner ring of the single bearing bush (31) and the outer surface of the shaft sleeve (33); the end cover (34) is installed at one end of the installation groove (41), a convex spigot (341) is arranged at one end, facing the inside of the installation groove (41), of the main body of the end cover (34), the convex spigot (341) and the inner cylindrical surface of the installation groove (41) form hole-shaft fit to complete radial positioning, and the end part of the convex spigot (341) abuts against the outer edge end face of the single bearing bush (31);

the magnetofluid bearing (3) further comprises an intermediate plate (32) and a pressure distribution assembly (36); the number of the single bearing bushes (31) is more than or equal to two, a plurality of the single bearing bushes (31) are arranged in the mounting groove (41) in an overlapped mode along the direction of the main shaft (2), the end faces of the seat rings (313) of the adjacent single bearing bushes (31) are abutted to carry out axial positioning, the middle plate (32) is a double-layer flat plate with an interlayer (321), the outer edge of the middle plate (32) is closed by a circular ring, air inlet holes (323) are formed in the circular ring, and a central hole (322) is formed in the middle of the middle plate (32); the middle plate (32) is arranged between the permanent magnets (311) of the adjacent single bearing bushes (31), the outer ring of the middle plate (32) is abutted against the inner ring of the seat ring (313), the diameter of the central hole (322) is larger than the outer diameter of the shaft sleeve (33), and the diameter of the central hole (322) is smaller than the outer diameter of a complete circle formed by the permanent magnets (311) and the isolating blocks (312) at the inner edge; the outer surface of the seat ring (313) is provided with an air passing groove (3131), the air passing groove (3131) extends from one side end face of the seat ring (313) to the other side end face, the air passing groove (3131) also extends from the outer edge to the inner ring on the end face of the seat ring (313), the air inlet hole (323) is connected with the air passing groove (3131), a pressure distribution component (36) is arranged in the axial section of the air passing groove (3131), the air passing groove (3131) close to the iron core (1) is connected to the inner space of the motor, an air inlet hole (42) is arranged on the wall surface of the machine shell (4), and protective air with pressure higher than the ambient pressure is introduced into the air inlet hole (42) from the outside.

2. The rotor multi-source constraint explosion-proof motor using the magnetofluid bearing is characterized in that: the end cover (34) is provided with a second connecting hole (343), one end of the second connecting hole (343) is connected with the end face, deviating from the iron core (1), of the end cover (34), one end of the second connecting hole is connected to the contact face, abutted to the seat ring (313), of the end cover (34), and the second connecting hole (343) is communicated with the air passing groove (3131).

3. The rotor multi-source constraint explosion-proof motor using the magnetofluid bearing is characterized in that: the air inlet hole (42) is located end cover (34), set up first hole (342) on end cover (34), air inlet hole (42) axial extension is connected, and first hole (342) is connected to air inlet hole (42) one end, and motor inner space is connected to one end, and first hole (342) and second hole (343) are sealed screw hole, and first hole (342) and second hole (343) are connected with external trachea through joint (39).

4. The rotor multi-source constraint explosion-proof motor using the magnetofluid bearing is characterized in that: annular groove (344) have been seted up on end cover (34), annular groove (344) are located first hole (342) and second hole (343) one end towards iron core (1) respectively, and annular groove (344) use main shaft (2) as the axis.

5. The rotor multi-source constraint explosion-proof motor using the magnetofluid bearing is characterized in that: cross gas groove (3131) and be located the axial section part on seat ring (313) outer face of cylinder for arc, join in marriage pressure subassembly (36) and include semicircle ring strip (361) and semicircle orifice plate (362), semicircle ring strip (361) are to the clamp with semicircle orifice plate (362) and are tightly installed in crossing gas groove (3131) axial section, have breach (3611) on the one end arc surface of semicircle ring strip (361), radial section of gas groove (3131) is closely close to in breach (3611).

Technical Field

The invention relates to the field of motors, in particular to a rotor multi-source constraint explosion-proof motor using a magnetic fluid bearing.

Background

The motor is a widely used prime mover and provides the original mechanical power for various structures.

In many occasions, such as most chemical engineering occasions, the use environment of the motor is full of inflammable gas, if inflammable and explosive gas reaches a high-temperature area of the motor, explosion can be caused, and serious accidents are caused, so the motor in the occasions has higher explosion-proof requirements.

In the prior art, the design of an explosion-proof motor mostly starts by isolating a high-temperature source or reducing the theoretical operating temperature, an isolated explosion-proof mode is not reliable, a position where a main shaft of the motor penetrates through a shell is a movable and static part, a running gap is bound to exist, and how to fully ensure that gas is not leaked from the position is an explosion-proof problem of the motor.

Disclosure of Invention

The invention aims to provide a rotor multi-source constraint explosion-proof motor using a magnetic fluid bearing, which aims to solve the problems in the prior art.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides an use rotor multisource restraint explosion-proof machine of magnetic fluid bearing, includes iron core, main shaft and casing, and the iron core is arranged in the casing, and iron core central authorities connect the main shaft, and the main shaft is outside the motor is stretched out from the casing tip, and explosion-proof machine still includes the magnetic fluid bearing, and the casing is set up the mounting groove by the position department that the main shaft passed, and the magnetic fluid bearing sets up in the mounting groove.

The magnetic fluid bearing not only plays a supporting role, but also has reliable sealing capability, can meet the requirement of the motor on the use in an explosion-proof occasion, prevents the explosive gas in the environment from entering the interior of the motor, and further causes explosion due to the high temperature of the iron core in the interior of the motor during operation.

Furthermore, the magnetic fluid bearing comprises a single bearing bush, a shaft sleeve, an end cover and a magnetic fluid, wherein the single bearing bush comprises a permanent magnet, an isolation block and a seat ring; the shaft sleeve is sleeved on the main shaft and is in transmission connection with the main shaft, the shaft sleeve is in key transmission or tight fit with the main shaft, and a sealing ring is arranged on the cylindrical contact surface of the shaft sleeve and the main shaft; the seat ring is arranged in the mounting groove, the outer ring of the seat ring is contacted with the inner cylindrical surface of the mounting groove, the outer edge of the permanent magnet is embedded in the inner ring of the seat ring, the inner edge of the permanent magnet is annular, the spacing block is filled between the inner edges of the adjacent permanent magnets, the permanent magnets and the spacing block form a complete cylindrical inner ring at the inner edges and are abutted against the outer surface of the shaft sleeve, and magnetic fluid is injected between the inner ring of the single bearing bush and the outer surface of the shaft sleeve; the end cover is installed in the one end of mounting groove, and the end cover main part sets up the tang towards the one end of mounting groove inslot, and the tang constitutes the hole axle cooperation with the mounting groove inner cylinder and accomplishes radial positioning, and the outer fringe terminal surface of the tight monomer axle bush in tip top of tang.

The shaft sleeve is sleeved on the main shaft, the shaft sleeve is used as a rotating body of the sliding bearing and is in bearing support with the static body-single bearing bush to form a sliding bearing structure, the main shaft is protected, even if the contact surface of the sliding bearing is in friction and abrasion, the shaft sleeve or the bearing bush is worn, corresponding parts can be replaced during maintenance, the main shaft does not need to be replaced, and therefore the maintenance cost is greatly reduced. The central position of the single bearing bush and the shaft sleeve are supported in a sliding mode, the magnetic fluid is injected into the contact surface to form a liquid lubricating layer, dry friction is prevented, the magnetic fluid is attracted by magnetic force and is kept on the contact surface of the bearing, a channel from the outside to the inside of the motor is blocked by the contact surface of the sliding bearing, the leakage channel is closed, and a sealing structure is formed. The single bearing bush is arranged in the mounting groove and is compressed through the end cover to complete position fixing. The isolation blocks are used for filling the inner edges of the permanent magnets which are not continuous into a ring shape into a complete ring shape, so that reliable cylindrical surface support is realized.

Furthermore, the magnetic fluid bearing also comprises an intermediate plate and a pressure distribution assembly; the number of the single bearing bushes is more than or equal to two, the single bearing bushes are arranged in the mounting groove in an overlapped mode along the direction of the main shaft, the end faces of seat rings of adjacent single bearing bushes are abutted to perform axial positioning, the middle plate is a double-layer flat plate with an interlayer, the outer edge of the middle plate is closed through a circular ring, an air inlet hole is formed in the circular ring, and a central hole is formed in the middle of the middle plate; the middle plate is arranged between the permanent magnets of the adjacent single bearing bushes, the outer ring of the middle plate is abutted against the inner ring of the seat ring, the diameter of the central hole is larger than the outer diameter of the shaft sleeve, the diameter of the central hole is smaller than the outer diameter of a complete circle formed by the permanent magnets and the isolating blocks at the inner edges, and the permanent magnets are not complete rings and are provided with gaps, so that the gaps are covered by the middle plate, namely the middle plate obstructs axial projection to cover a blank area on the single bearing bushes, and gas channeling from one side of each single bearing bush to the other side is prevented; the outer surface of the seat ring is provided with an air passing groove, the air passing groove extends from one side end face of the seat ring to the other side end face, the air passing groove also extends from the outer edge to the inner ring on the end face of the seat ring, namely, a bent groove is dug on the outer edge of the seat ring, an air inlet hole is connected with the air passing groove, a pressure distribution assembly is arranged in the axial section of the air passing groove, the air passing groove close to the iron core is connected to the inner space of the motor, the end part of the air passing groove far away from the iron core is connected to the outside atmosphere or the air passing hole in the end cover, the wall surface of the shell is provided with an air inlet hole, and protective air with the pressure larger than the ambient pressure is introduced into the air inlet hole from the outside.

The monomer axle bush that the pile set up can expand sliding bearing's support area to can reply different loads, the monomer axle bush of multistage installation supports respectively, can set up and support richly, so that when certain monomer axle bush takes place wearing and tearing, remaining axle bush still can play the bearing support effect, shut down when the right moment and maintain and change, change also only need change the axle sleeve or take place the monomer axle bush of wearing and tearing can, need to change all the other parts, reduce the replacement cost of vulnerable part.

Moreover, the single bearing bushes installed in a grading manner can also play a role in enhancing sealing and explosion-proof performance, the explosion-proof motor is sometimes not in a normal pressure state in use occasions, for example, a motor is arranged in a tank body and used for providing main rotating power for other parts, and the space in the tank body is an area where explosive gas is gathered, so that magnetic fluid on the contact surface between the bearing bushes and the bearing bushes can be blown by the pressure difference between the original air in the motor and the use environment of the motor, after the magnetic fluid is blown away from the contact surface, the dry friction between the bearing bushes and the bearing bushes is secondary damage, and the larger damage is that surrounding explosive gas enters the motor and further causes explosion, which is unacceptable, and the magnetic force increase of the permanent magnet can slightly improve the capacity of the magnetic fluid film for resisting the pressure difference between two sides, but the improvement is limited. According to the invention, the single bearing bushes are arranged in multiple stages, and the protective gas with sequentially changed pressure is introduced between stages, so that the pressure on two sides of the magnetic fluid film on a single stage is reduced, and the magnetic fluid film is not easily blown away. The protective gas can be some inert gases, and is filled between each stage of bearing bush to separate the interior of the charger from the external environment.

The invention obtains the graded pressure by respectively taking gas from a gas flow path, protective gas is filled into the motor from the wall surface of the shell, then flows along the gas passing grooves on the monomer bearing bushes of each grade and finally reaches the external environment of the motor or is collected by a pipeline, on the flow path, a pressure distribution assembly is arranged on the axial section of the gas passing groove of each grade, the pressure distribution assembly is flow resistance, the gas generates pressure drop when flowing through the pressure distribution assembly, thereby obtaining the pressure value which decreases step by step from the inside of the motor to the outside, the gas enters the interlayer through the radial section of the gas passing groove and the gas inlet hole of the middle plate and maintains the pressure in the interlayer, and the pressure difference of the magnetic fluid at the inner ring of the single grade is the pressure drop value generated by the gas flowing through the pressure distribution assembly, the value can be large or small, the adjustment is carried out through the pressure distribution assembly, the pressure difference which can be received by the magnetic fluid is matched, and the damage of the liquid lubricating film is prevented.

In addition, the interlayer can also contain some magnetic fluid, and the magnetic fluid lost or volatilized on the rotating contact surface can be supplemented in the operation process, so that the long-term maintenance of the liquid lubricating film is ensured.

Furthermore, set up the second on the end cover and connect the hole, the second connects the terminal surface that the end cover deviates from the iron core, one end is connected to the end cover and is connected to the contact surface that the seat ring is inconsistent, the second connects the hole and passes the gas tank and communicate mutually. The second connects the hole setting back, be about to protective gas and collect the backward flow, protective gas collects the backward flow, can not count the material loss of protective gas, only pressure loss appears, through booster pump pressure boost circulation, the protective gas that the circulation was got up, can be with great flow operation, protective gas can flow through inside the motor, so, can take away partly iron core heat, and then there is the cooling effect to the motor, it can to cool off on the partial pipeline that protective gas is located outside the motor, if directly atmospheric, protective gas need be continuous provide new, old protective gas blows in the surrounding air, consume too greatly, do not have practical meaning.

Further, the inlet port is located end cover department, sets up first hole that connects on the end cover, and the inlet port axial extension is connected, and first hole that connects is connected to inlet port one end, and motor inner space is connected to one end, and first hole and second connect the hole and be sealed screw hole, and first hole and second connect the hole to be connected with external trachea through connecting.

The first connecting hole and the second connecting hole are used as an inlet and an outlet of protective gas and are positioned at the same position to facilitate the connection.

Further, the end cover is provided with a ring groove, the ring groove is respectively located at the first connecting hole and the second connecting hole towards one end of the iron core, and the ring groove uses the main shaft as an axis. If there is not the annular, first connect the hole need directly to going up the air pocket on the circumference angle, the second connects the hole and need directly connect the one end of air passing groove on the circumference angle, and the installation angle of end cover only has one promptly, and after adding the annular, just need not to consider the circumference angle during the installation end cover.

Preferably, the joint is a ferrule type joint. The cutting sleeve type joint is convenient for connecting the air pipe.

Alternatively, the air inlet can also be arranged on the wall surface of the casing far away from the magnetofluid bearing. Namely: the protective gas introduced into the motor can fully flow through the iron core and then is discharged out of the motor from the magnetic fluid bearing, so that the heat is taken away more completely, and the protective gas is only slightly inconvenient because the position distance on the connecting pipe is far away.

Further, cross the axial section part that the gas tank is located the outer face of cylinder of seat ring and be convex, join in marriage and press the subassembly to include semicircle orifice bar and semicircle orifice plate, have the semicircle orifice plate in a plurality of kinds of apertures to select to use, the pressure drop that can take place the difference when gaseous passing through, the semicircle orifice bar supports the semicircle orifice plate to press from both sides tightly and installs in crossing gas tank axial section, has the breach on the one end arc surface of semicircle orifice bar, the radial section of gas tank is crossed to the breach next-door neighbour.

The semicircular ring strip and the semicircular hole plate are placed in the axial section of the gas passing groove, the small hole of the semicircular hole plate is the occurrence position of partial pressure drop when gas flows through, the semicircular ring strip is a structural component which is arranged at the installation position of the semicircular hole plate, and the notch at one end of the semicircular ring strip enables gas to be smoothly bent to reach the gas inlet and then enter each interlayer.

Compared with the prior art, the invention has the beneficial effects that: the magnetic fluid bearing is used for not only reliably supporting the motor shaft, but also performing perfect dynamic sealing, so that the danger caused by the explosive gas entering the motor in the use environment is prevented; the multi-stage overlapped single bearing bush can selectively expand the supporting area of the sliding bearing to cope with different loads; when a certain single bearing bush is worn, the rest bearing bushes can still play a bearing supporting role, the machine is stopped at a proper time for maintenance and replacement, only the shaft sleeve or the worn single bearing bush needs to be replaced, and the rest parts need to be replaced, so that the replacement cost of a quick-wear part is reduced; the single bearing bushes are installed in a grading manner, and protective gas with grading pressure is introduced between stages, so that the pressure difference between two sides of each single bearing bush is controlled, a liquid lubricating film on a bearing contact surface is not damaged, the lubricating condition is improved, the sealing effect is enhanced, the anti-explosion performance of the motor can be ensured by enhancing the sealing capability, a part of magnetic fluid can be accommodated in an area between the graded single bearing bushes, and the magnetic fluid consumed in the motor running process is supplemented; the protective gas flowing through the interior of the motor can carry away the heat of the motor.

Drawings

In order that the present invention may be more readily and clearly understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings.

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the spindle extending out of the housing according to the present invention;

FIG. 3 is view A-A of FIG. 2;

FIG. 4 is a perspective view of a single bearing shell according to the present invention;

FIG. 5 is view B of FIG. 4;

FIG. 6 is a sectional view of the intermediate plate of the present invention;

FIG. 7 is a cut-away schematic view of the end closure of the present invention;

FIG. 8 is a perspective view of the pressure distribution assembly of the present invention;

FIG. 9 is a perspective exploded view of the magnetofluid bearing of the present invention;

FIG. 10 is a schematic illustration of the operation of the present invention;

fig. 11 is view C of fig. 10.

In the figure: 1-iron core, 2-main shaft, 3-magnetofluid bearing, 31-single bearing bush, 311-permanent magnet, 312-isolation block, 313-seat ring, 3131-air passing groove, 32-middle plate, 321-interlayer, 322-center hole, 323-air inlet hole, 33-shaft sleeve, 34-end cover, 341-convex spigot, 342-first connecting hole, 343-second connecting hole, 344-ring groove, 35-magnetofluid, 36-pressure matching component, 361-semicircular ring strip, 3611-notch, 362-semicircular hole plate, 39-joint, 4-machine shell, 41-mounting groove and 42-air inlet hole.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 and 2, the rotor multi-source constraint explosion-proof motor using the magnetic fluid bearing comprises an iron core 1, a main shaft 2 and a casing 4, wherein the iron core 1 is arranged in the casing 4, the main shaft 2 is connected to the center of the iron core 1, the main shaft 2 extends out of the motor from the end part of the casing 4, the explosion-proof motor further comprises the magnetic fluid bearing 3, a mounting groove 41 is formed in the position, through which the main shaft 2 penetrates, of the casing 4, and the magnetic fluid bearing 3 is arranged in the mounting groove 41.

The magnetic fluid bearing not only plays a supporting role, but also has reliable sealing capability, can meet the use requirement of the motor in an explosion-proof occasion, prevents the explosive gas of the environment from entering the interior of the motor, and further causes explosion due to the high temperature of the iron core 1 in the interior of the motor during operation.

As shown in fig. 2, the magnetic fluid bearing 3 includes a single bearing bush 31, a shaft sleeve 33, an end cap 34 and a magnetic fluid 35, wherein the single bearing bush 31 includes a permanent magnet 311, a spacer block 312 and a seat ring 313; the shaft sleeve 33 is sleeved on the main shaft 2 and is in transmission connection with the main shaft 2, key transmission or tight fit is achieved, and a sealing ring is arranged on the cylindrical contact surface of the shaft sleeve 33 and the main shaft 2; the seat ring 313 is arranged in the mounting groove 41, the outer ring of the seat ring 313 is contacted with the inner cylindrical surface of the mounting groove 41, the outer edge of the permanent magnet 311 is embedded in the inner ring of the seat ring 313, the inner edge of the permanent magnet 311 is annular, the spacing block 312 is padded between the inner edges of the adjacent permanent magnets 311, the permanent magnets 311 and the spacing block 312 form a complete cylindrical inner ring at the inner edge and are abutted against the outer surface of the shaft sleeve 33, and the magnetic fluid 35 is injected between the inner ring of the single bearing bush 31 and the outer surface of the shaft sleeve 33; the end cover 34 is installed at one end of the installation groove 41, a male spigot 341 is arranged at one end of the main body of the end cover 34 facing the inside of the installation groove 41, the male spigot 341 and the inner cylindrical surface of the installation groove 41 form a hole-shaft fit to complete radial positioning, and the end part of the male spigot 341 tightly pushes against the outer edge end surface of the single bearing bush 31.

The shaft sleeve 33 is sleeved on the main shaft 2, the shaft sleeve 33 is used as a rotating body of a sliding bearing and is in bearing support with the static body-single bearing bush 31 to form a sliding bearing structure, the main shaft 2 is protected, even if the contact surface of the sliding bearing is in friction wear, the worn part is the shaft sleeve or the bearing bush part, corresponding parts can be replaced during maintenance, and the main shaft 2 does not need to be replaced, so the maintenance cost is greatly reduced. The central position of the single bearing bush 31 and the shaft sleeve 33 are supported in a sliding mode, the magnetic fluid 35 is injected into the contact surface to form a liquid lubricating layer, dry friction is prevented, the magnetic fluid 35 is attracted by magnetic force and is kept on the contact surface of the bearing, a channel from the outside to the inside of the motor is blocked by the contact surface of the sliding bearing, a leakage channel is sealed, and a sealing structure is formed. The single bearing bush 31 is installed in the installation groove 41 and is pressed tightly by the end cover 34, and the position fixing is completed. The spacer 312 is used to fill the inner edge of the permanent magnet 311 that is not continuous in a ring shape into a complete ring shape, thereby realizing reliable cylindrical surface support.

As shown in fig. 2 to 9, the magnetohydrodynamic bearing 3 further includes an intermediate plate 32 and a pressure distribution assembly 36; the number of the single bearing bushes 31 is greater than or equal to two, a plurality of the single bearing bushes 31 are arranged in the mounting groove 41 in an overlapped mode along the direction of the main shaft 2, the end faces of the seat rings 313 of the adjacent single bearing bushes 31 are abutted to each other for axial positioning, the middle plate 32 is a double-layer flat plate with an interlayer 321, the outer edge of the middle plate 32 is closed by a circular ring, an air inlet hole 323 is formed in the circular ring, and a central hole 322 is formed in the middle of the middle plate 32; the middle plate 32 is arranged between the permanent magnets 311 of the adjacent single bearing bushes 31, the outer ring of the middle plate 32 abuts against the inner ring of the seat ring 313, the diameter of the central hole 322 is larger than the outer diameter of the shaft sleeve 33, the diameter of the central hole 322 is smaller than the outer diameter of a complete circle formed by the permanent magnets 311 and the spacing block 312 at the inner edge, and the permanent magnets are not complete circles and are provided with gaps, so that the positions of the gaps are covered by the middle plate 32, namely the middle plate 32 obstructs axial projection to cover a blank area on the single bearing bushes 31, and gas on one side of each single bearing bush 31 is prevented from flowing to the other side; as shown in fig. 5, an air passing groove 3131 is formed in an outer surface of the seat ring 313, the air passing groove 3131 extends from one end surface of the seat ring 313 to the other end surface, the air passing groove 3131 also extends from an outer edge to an inner edge on the end surface of the seat ring 313, that is, a bent groove is dug in the outer edge of the seat ring 313, the air inlet hole 323 is connected to the air passing groove 3131, a pressure distribution assembly 36 is disposed in an axial section of the air passing groove 3131, the air passing groove 3131 next to the iron core 1 is connected to an internal space of the motor, an end of the air passing groove 3131 far away from the iron core 1 is connected to an external atmosphere or an air passing hole in the end cover 34, an air inlet hole 42 is formed in a wall surface of the housing 4, and the air inlet hole 42 introduces shielding gas from the external environment, wherein the pressure of the shielding gas is greater than the ambient environment.

The monomer axle bush 31 of the pile-up setting can expand the support area of slide bearing to can deal with different loads, the monomer axle bush of multistage installation supports respectively, can set up and support the surplus, so that when a certain monomer axle bush 31 takes place wearing and tearing, remaining axle bush still can play the bearing support effect, shut down when appropriate time and maintain and change, change also only need change the axle sleeve or take place wearing and tearing monomer axle bush 31 can, need to change all the other parts, reduce the replacement cost of wearing parts.

Moreover, the single bearing bush 31 installed in stages can also play a role in enhancing sealing and explosion-proof performance, and the explosion-proof motor is sometimes not in a normal pressure state in use occasions, for example, a motor is arranged in a tank body to provide main rotating power for other parts, and the space in the tank body is an area where explosive gas is gathered, so that the magnetic fluid 35 on the contact surface between the bearing bush and the bearing bush can be blown by the pressure difference between the original air in the motor and the use environment of the motor, when the magnetic fluid 35 is blown away from the contact surface, the dry friction between the bearing bush and the bearing bush is secondary hazard, and the larger hazard is that the surrounding explosive gas enters the motor to cause explosion, which is unacceptable, and the magnetic force increase of the permanent magnet 31 can slightly improve the capacity of the magnetic fluid film for resisting the pressure difference between two sides, but the improvement is limited. According to the invention, the single bearing bushes 31 are arranged in multiple stages, and the protective gas with sequentially changed pressure is introduced between stages, so that the pressure on two sides of the magnetic fluid film on a single stage is reduced, and the magnetic fluid film is not easily blown away. The protective gas can be some inert gases, and is filled between each stage of bearing bush to separate the interior of the charger from the external environment.

The gas of each stage pressure is too troublesome if it is separately filled and sealed before operation, so the present invention achieves the staged pressure obtaining by separately taking gas from a gas flow path, as shown in fig. 10, the shielding gas is filled into the motor from the wall surface of the housing 4, then flows along the gas passing groove 3131 of each stage of the single bearing bush 31, and finally reaches the external environment of the motor or is collected by a pipe, on the flow path, the pressure distribution assembly 36 is arranged on the axial section of the gas passing groove 3131 of each stage, the pressure distribution assembly 36 is a flow resistance, the gas is subjected to pressure drop while flowing through the pressure distribution assembly 36, so as to obtain the pressure values gradually decreased from the motor interior to the exterior, enters the interlayer 321 through the radial section of the gas passing groove 3131 and the gas inlet hole 323 of the middle plate 32, and maintains the pressure therein, the pressure difference that the magnetic fluid 35 is subjected to the inner ring 31 of the single stage is the pressure drop value generated by the gas flowing through the pressure distribution assembly 36, the value can be large or small, the pressure distribution component 36 is used for adjusting the pressure difference, the pressure difference can be matched with the magnetic fluid, and the liquid lubricating film is prevented from being damaged.

In addition, the interlayer 321 can also contain some magnetic fluid 35, and the magnetic fluid lost or volatilized on the rotating contact surface can be supplemented in the operation process, so that the long-term maintenance of the liquid lubricating film is ensured.

When different numbers of single bearing bushes 31 need to be installed, because the axial depth of the installation groove 41 is not convenient to modify, the end cover 34 is used for compensation, as shown in fig. 7, when the number is reduced, the size L in fig. 7 is increased, vice versa, the axial distance adjustment can be carried out through more universal gaskets, and the part in the size L in fig. 7 is replaced by a plurality of gaskets which can carry out radial and circumferential positioning.

As shown in fig. 7, a second connection hole 343 is provided in the end cover 34, one end of the second connection hole 343 is connected to an end face of the end cover 34 away from the iron core 1, one end of the second connection hole 343 is connected to a contact surface of the end cover 34 abutting against the seat ring 313, and the second connection hole 343 is in communication with the air passing groove 3131. The second connects the hole 343 to set up the back, be about to protective gas and collect the backward flow, protective gas collects the backward flow, can not count the material loss of protective gas, pressure loss only appears, through booster pump pressure boost circulation, the protective gas that the circulation got up, can be with great flow operation, protective gas can flow through inside the motor, so, can take away partly iron core 1 heat, and then there is the cooling effect to the motor, it can to cool off on the partial pipeline that protective gas is located outside the motor, if directly atmospheric, protective gas need be continuous provide new, old protective gas blows to in the surrounding air, consume too greatly, do not have practical meaning.

As shown in fig. 2, the air inlet hole 42 is located at the end cover 34, a first connecting hole 342 is formed in the end cover 34, the air inlet hole 42 extends axially and is connected, one end of the air inlet hole 42 is connected with the first connecting hole 342, one end of the air inlet hole is connected with the inner space of the motor, the first connecting hole 342 and the second connecting hole 343 are sealed threaded holes, and the first connecting hole 342 and the second connecting hole 343 are connected with an external air pipe through a joint 39.

The first connection hole 342 and the second connection hole 343 are used as the inlet and outlet of the shielding gas and are located at the same position to facilitate the connection.

As shown in fig. 7 and 11, the end cover 34 is provided with a ring groove 344, the ring groove 344 is respectively located at the first connecting hole 342 and the end of the second connecting hole 343 facing the iron core 1, and the ring groove 344 uses the spindle 2 as an axis. Without the ring groove 344, the first connection hole 342 needs to be directly aligned with the upper air inlet 42 in a circumferential angle, and the second connection hole 343 needs to be directly connected with one end of the air passing groove 3131 in a circumferential angle, that is, the installation angle of the end cap 34 is only one, and after the ring groove 344 is added, the end cap 34 is installed without considering the circumferential angle.

The joint 39 is a ferrule type joint. The cutting sleeve type joint is convenient for connecting the air pipe.

The air inlet holes 42 may also be provided in the wall of the housing 4 remote from the magnetofluid bearing 3. Namely: the protective gas introduced into the motor can fully flow through the iron core 1 and then is discharged out of the motor from the magnetic fluid bearing 3, so that the heat is taken away more completely, and the protective gas is only slightly inconvenient because the position distance on the connecting pipe is far away.

As shown in fig. 5 and 8, the axial section of the air passing groove 3131 on the outer cylindrical surface of the seat ring 313 is in the shape of an arc, the pressure distribution assembly 36 includes a semicircular ring strip 361 and a semicircular orifice plate 362, the semicircular orifice plate 362 with several apertures can be used alternatively, different pressure drops can occur when air passes through the pressure distribution assembly, the semicircular ring strip 361 clamps the semicircular orifice plate 362 in a tight fit manner in the axial section of the air passing groove 3131, one end of the semicircular ring strip 361 has a notch 3611, and the notch 3611 is close to the radial section of the air passing groove 3131.

The semicircular strip 361 and the semicircular orifice plate 362 are placed in the axial section of the air passing groove 3131, the small hole of the semicircular orifice plate 362 is the local pressure drop when the air flows through, the semicircular strip 361 is a structural component arranged at the installation position of the semicircular orifice plate 362, and the notch 3611 at one end of the semicircular strip 361 enables the air to smoothly bend to reach the air inlet 323 and then enter each interlayer 321.

The main using process of the invention is as follows: the inert gas is introduced into the motor from the first connecting hole 342 from the outside, the inert gas flows in the gas passing groove 3131 adjacent to the iron core 1 in a bending mode, then flows step by step and is reduced in pressure by the semicircular hole plate 362, and finally flows out of the device through the second connecting hole 343, and the graded pressure is introduced into the middle plate 32 between the adjacent monomer bearing bushes 31, so that the magnetic fluid 35 at the inner ring of the monomer bearing bush 31 is only subjected to a small pressure difference, a liquid film can be reliably reserved, the shaft sleeve 33 and the monomer bearing bush 31 are fully lubricated, the inside of the motor is fully isolated from the external environment, and the danger caused when the explosive gas reaches the high-temperature part of the motor is prevented.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.