CN220979853U - A new type of magnetic coupling single screw pump - Google Patents

Abstract

The utility model discloses a novel magnetic coupling single-screw pump, which comprises a shell, a motor and a magnetic coupler, wherein a stator and a rotor are arranged in the shell, an inlet cavity and an outlet are arranged on the shell, a transmission shaft connected with one end of the rotor is arranged in the inlet cavity, the motor is connected with one end of the transmission shaft through the magnetic coupler, the transmission shaft is a flexible rod, and the other end of the flexible rod is connected with one end of the rotor through the flexible coupler. The flexible shaft coupling and the flexible rod are used for replacing a mechanical universal joint in a traditional screw pump, the flexible rod and the rotor are connected with the flexible shaft coupling through the key slot, the flexible shaft coupling can play a good eccentric transmission role, compared with the universal joint, the flexible rod is lighter and more skillful, the flexible shaft coupling device can be better positioned axially when being used, the problem of corrosive pollution of conveying liquid can be effectively avoided by adopting the flexible shaft coupling and the flexible rod, and the sealing is reliable.

Description

A new type of magnetic coupling single screw pump

Technical Field

The utility model relates to the technical field of screw pumps, in particular to a novel magnetically coupled single screw pump.

Background technique

The single screw pump is a rotor type positive displacement pump, which relies on the meshing of the screw and the bushing to produce volume changes between the suction chamber and the discharge chamber to transfer liquid. It is an internal meshing closed screw pump, and the main working parts are composed of a bushing (stator) with a double-headed spiral cavity and a single-headed spiral screw (rotor) meshing with it in the stator cavity. When the input shaft drives the rotor to make planetary rotation around the center of the stator through the universal joint, the stator-rotor pair continuously meshes to form a sealed cavity, and these sealed cavities make uniform axial motion without changing the volume, and the transmission medium is transmitted from the suction end to the output end through the stator-rotor pair. The medium sucked into the closed cavity flows through the stator without being stirred or damaged.

In traditional single-screw pumps, in order to achieve rotational motion at the stator and rotor, a universal joint is required to provide eccentric transmission; the internal structure of the universal joint is very complex, so a universal joint sleeve is usually required to provide protection; and when the single-screw pump works for too long, its sleeve will wear out, causing impurities inside the universal joint to corrode into the conveying liquid, causing contamination of the conveying liquid.

In traditional single-screw pumps, the power and torque are transmitted through the motor acting on the coupling, then from the coupling to the drive shaft, then from the drive shaft to the universal joint, and finally the power acts from the universal joint to the rotor, and finally the liquid is transported through the planetary rotation between the rotor and the stator. In traditional single-screw pumps, the coupling and the drive shaft, the drive shaft and the universal joint, and the universal joint and the rotor are all connected by traditional mechanical contact. Because of its traditional mechanical connection method, a series of sealing devices need to be installed and designed when the single-screw pump is put into use. Although there are many good sealing methods and designs on the market, their sealing properties will fail due to a series of reasons, thereby affecting the input liquid, the performance of the pump, and the performance of the motor.

The universal joint and transmission shaft connection of the single screw pump must ensure that the liquid medium at the inlet cavity will not affect the bearing, skeleton oil seal and other shaft seal components at the bearing seat, and even the motor. Therefore, the selection and design of the sealing device at the inlet cavity and the bearing seat is very important. However, no matter how it is designed, since the universal joint and the transmission shaft of the traditional screw pump are connected by contact, there will always be gaps and it is impossible to achieve a completely sealed environment. With the deterioration of the working environment and the increase in the number of years of product use, it is easy to cause leakage and wear problems, so that the medium affects the pump and causes damage to the pump.

For example, Chinese patent CN105207528A discloses a combined magnetic coupler and a multi-operating-condition variable-load twin-screw pump driven by the same. The driving shaft drives the pump shaft to rotate through the magnetic force, thereby realizing contactless torque and kinetic energy transmission through the wall of the device. Although contactless transmission can be achieved, the subsequent transmission is still mechanical, and there are still problems of corrosion and sealing failure.

Utility Model Content

In view of the deficiencies in the prior art, the utility model provides a novel magnetically coupled single-screw pump, which can effectively avoid the problem of corrosion and contamination of the conveying liquid and has reliable sealing.

In order to solve the above technical problems, the technical solution adopted by the utility model is:

The novel magnetically coupled single-screw pump comprises a housing, a motor and a magnetic coupler. The housing is provided with a stator and a rotor. The housing is provided with an inlet cavity and an outlet. The inlet cavity is provided with a transmission shaft connected to one end of the rotor. The motor is connected to one end of the transmission shaft through the magnetic coupler. The transmission shaft is a flexible rod. The other end of the flexible rod is connected to one end of the rotor through a flexible coupling.

further:

The rotating shaft of the motor is connected to the magnetic coupling through another coupling.

The magnetic coupler includes a magnetic inner rotor structure, a magnetic outer rotor structure and an isolation sleeve. An opening is provided on the shell corresponding to the inlet cavity, and the isolation sleeve is arranged at the opening. The magnetic outer rotor structure is located on one side of the isolation sleeve and connected to the end of the flexible rod, and the magnetic inner rotor structure is located on the other side of the isolation sleeve and connected to the rotating shaft of the motor.

The isolation sleeve is a cylindrical structure, and the magnetic outer rotor structure is located inside the cylindrical structure.

The end of the flexible rod is inserted into the magnetic outer rotor structure, and the magnetic outer rotor structure is connected to the end of the flexible rod through a keyway.

The shell comprises a side shell, an intermediate shell and another side shell which are connected in sequence. The stator and the rotor are arranged in one side shell, the inlet cavity and the magnetic outer rotor structure are arranged in the intermediate shell, and the magnetic inner rotor structure is arranged in the other side shell.

The isolation sleeve is a double-sealed isolation sleeve, which comprises an inner sealing isolation sleeve and an outer sealing isolation sleeve which are compounded together. The inner sealing isolation sleeve is a metal sleeve, and the outer sealing isolation sleeve is a ceramic sleeve.

The magnetic inner rotor structure includes an inner rotor radial steel body and an inner rotor axial steel body. The inner rotor radial steel body is a cylindrical structure with openings at both ends. The inner rotor axial steel body is connected to one end of the cylindrical structure through a fastener. Magnets are provided on the inner rotor radial steel body and the inner rotor axial steel body.

Compared with the prior art, the utility model has the following advantages:

The new magnetically coupled single-screw pump has a reasonable structural design and uses a flexible coupling and a flexible rod to replace the mechanical universal joint in a traditional screw pump. The flexible rod and the rotor are connected to the flexible coupling through a keyway. The flexible coupling can play a good eccentric transmission role, and the flexible rod is lighter than the universal joint, so it can achieve better axial positioning when using a magnetic coupling device. The use of a flexible coupling and a flexible rod can effectively avoid corrosion and contamination of the conveying liquid, and the sealing is reliable.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a brief description of the contents expressed in each of the drawings of this specification and the symbols in the drawings:

Fig. 1 is the general diagram of the screw pump of the utility model.

FIG. 2 is an enlarged schematic diagram of the magnetic coupler of the present invention.

FIG3 is a schematic diagram of the structure of the inner rotor of the utility model.

FIG4 is a schematic diagram of the structure of the outer rotor of the utility model.

FIG5 is a schematic diagram of the structure of the isolation sleeve of the utility model.

FIG. 6 is a detailed diagram of the radial magnetic coupler of the present invention.

FIG. 7 is a schematic diagram of the structural dimension codes of the radial magnetic coupling transmission of the present invention.

FIG8 is a detailed diagram of the axial magnetic coupling device of the present invention.

FIG. 9 is a schematic diagram of the structural dimension codes of the axial magnetic coupling transmission of the present utility model.

FIG10 is a schematic diagram showing the principle of torque transmission by the combined pull-push magnetic circuit of the utility model.

FIG. 11 is a detailed diagram of the ferromagnetic body of the present invention.

FIG. 12 is a wiring diagram of the ferromagnetic body of the present invention.

In the figure:

1 outlet, 2 stator, 3 rotor, 4 inlet cavity, 5 flexible coupling, 6 flexible rod, 7 bearing seat, 8 shaft seal assembly, 9 coupling, 10 safety cover, 11 motor, 12 base,

13 magnetic coupling, 1301 inner rotor radial steel body, 1302 inner rotor axial steel body, 1303 inner rotor axial magnet, 1304 inner rotor radial magnet, 1305 isolation sleeve, 130501 metal sealing isolation sleeve, 130502 ceramic sealing isolation sleeve, 1306 outer rotor radial steel body, 1307 outer rotor radial magnet, 1308 outer rotor axial magnet, 1309 outer rotor axial steel body,

14 connecting shaft, 15 bearing seat end cover, tct1 ferromagnetic support frame, tct2 ferromagnetic support mechanism coil connecting power line extension port, tct3 ferromagnet, tct4 coil.

Detailed ways

The specific implementation of the utility model will be further explained in detail below through the description of embodiments with reference to the accompanying drawings.

As shown in Figures 1 to 12, the new magnetically coupled single-screw pump includes a housing, a motor 11 and a magnetic coupler 13. A stator 2 and a rotor 3 are provided in the housing. An inlet cavity 4 and an outlet 1 are provided on the housing. A transmission shaft connected to one end of the rotor is provided in the inlet cavity. The motor is connected to one end of the transmission shaft through the magnetic coupler. The transmission shaft is a flexible rod 6. The other end of the flexible rod is connected to one end of the rotor through a flexible coupling 5.

The utility model uses a flexible coupling and a flexible rod to replace the mechanical universal joint in a traditional screw pump. The flexible rod and the rotor are connected to the flexible coupling through a keyway. The flexible coupling can play a good eccentric transmission role, and the flexible rod is lighter than the universal joint, and can achieve better axial positioning when using a magnetic coupling device. The use of the flexible coupling and the flexible rod can effectively avoid the problem of corrosion and contamination of the conveying liquid, and the sealing is reliable.

The rotating shaft of the motor 11 is connected to the magnetic coupler through another coupling 9; the magnetic coupler includes a magnetic inner rotor structure, a magnetic outer rotor structure and an isolation sleeve 1305, an opening is provided on the shell corresponding to the inlet cavity, the isolation sleeve is arranged at the opening, the magnetic outer rotor structure is located on one side of the isolation sleeve and connected to the end of the flexible rod, and the magnetic inner rotor structure is located on the other side of the isolation sleeve and connected to the rotating shaft of the motor.

A magnetic coupling consists of two main parts: the driver and the driven part. On the driver side, there is usually an external drive source, such as a motor, which transfers power to the drive part inside the magnetic coupling through mechanical components. This drive part contains a rotating magnet, also called a driver pole. When the external drive source rotates, it creates a rotating magnetic field. On the driven side, the driven part of the magnetic coupling contains a receiving pole, also called a driven pole. When the driver pole rotates, its rotating magnetic field acts on the driven pole, transferring power to the driven part through the magnetic field.

In order to solve the problem of the universal joint in the transmission single screw pump being prone to corrosion of the conveying fluid, a flexible rod and a flexible coupling were selected; the flexible coupling has good protection, small volume, and can play an eccentric transmission role; the flexible rod structure is simpler than the universal joint; the use of a flexible rod and a flexible coupling combination can effectively solve the problem of the universal joint part in the traditional single screw pump being prone to corrosion of the conveying fluid. In order to solve the leakage and wear problems that are easy to cause in traditional single screw pumps, a magnetic coupling, a device that can achieve contactless transmission of power and torque, was selected; the magnetic coupling is a device that transmits force and power through a magnetic field, used to connect and transmit rotational power without mechanical contact; the working principle of the magnetic coupling is based on the interaction of magnetic fields without the need for physical contact; this means that when using a magnetic coupling, the drive end and the driven end can be isolated, which can better prevent leakage of the medium or the entry of external contaminants.

The shell includes a side shell, an intermediate shell and another side shell connected in sequence. The stator and the rotor are arranged in the one side shell, the inlet cavity and the magnetic outer rotor structure are arranged in the intermediate shell, and the magnetic inner rotor structure is arranged in the other side shell. The isolation sleeve is a cylindrical structure, and the magnetic outer rotor structure is located inside the cylindrical structure; the end of the flexible rod is inserted into the magnetic outer rotor structure, and the magnetic outer rotor structure is connected to the end of the flexible rod through a keyway, with a compact structure and reliable sealing. A bearing seat 7, a bearing and a shaft seal assembly 8 are provided corresponding to the magnetic inner rotor structure, a bearing seat end cover 15 is provided at the end of the bearing seat, and a safety cover 10 is provided corresponding to the coupling; the entire pump housing and the motor are arranged on the same base 12, and the operation is stable and reliable.

The magnetic inner rotor structure includes an inner rotor radial steel body 1301 and an inner rotor axial steel body 1302. The inner rotor radial steel body is a cylindrical structure with openings at both ends. The inner rotor axial steel body is connected to one end of the cylindrical structure through fasteners. Magnets are provided on the inner rotor radial steel body and the inner rotor axial steel body, and the structure is compact.

The preferred specific examples of the present utility model are:

This patent uses a flexible coupling and a flexible rod to replace the universal joint in a traditional screw pump; the flexible rod and the rotor are connected to the flexible coupling through a keyway. The flexible coupling can play a good eccentric transmission role, so it is very suitable to replace the universal joint. In addition, the flexible rod is lighter than the universal joint, and can achieve better axial positioning when using a magnetic coupling device; and the use of a flexible coupling and a flexible rod will not have a great impact on the contamination of the conveying fluid.

In the magnetic coupler 13 of the present patent, the driving end is the inner rotor, and the inner rotor radial steel body 1301, the inner rotor axial steel body 1302, the inner rotor axial magnet 1303, and the inner rotor radial magnet 1304 in the present patent are the inner rotor component structure. The driven end is the outer rotor, and the outer rotor radial steel body 1306, the outer rotor radial magnet 1307, the outer rotor axial magnet 1308, and the outer rotor axial steel body 1309 in the present patent are the outer rotor component structure. When the motor drives the transmission shaft to rotate, the inner rotor axial magnet 1303 and the inner rotor radial magnet 1304 at the driving end will be driven to rotate so that it generates a rotating magnetic field. At the driven end, the driven part of the magnetic coupler receives the outer rotor radial magnet 1307 and the outer rotor axial magnet 1308. When 1303 and 1304 rotate, their rotating magnetic fields act on 1307 and 1308, and transmit power to the entire outer rotor through the magnetic field, thereby driving the rotational motion of the outer rotor part and achieving the purpose of contactless power transmission.

As shown in FIG3 , the inner rotor structure is connected to the linkage shaft 14 through a keyway. The inner rotor is connected by a disc block and a cylindrical block by bolts. The inner rotor axial magnet 1303 and the inner rotor axial steel body 1302 are embedded in the disc block, and the inner rotor radial steel body 1301 and the inner rotor radial magnet 1304 are embedded in the cylindrical block. As shown in FIG5 and FIG3 , the selected inner rotor axial magnet 1303 and inner rotor radial magnet 1304 are assembled by two kinds of magnets, which are permanent magnets and ferromagnets, respectively, and the ferromagnets are embedded inside the permanent magnets. When the motor drives the transmission shaft to rotate, the ferromagnets can play a role in constructing magnetic circuits, guiding and concentrating magnetic fields. Permanent magnets generate a persistent and stable magnetic field. In the inner rotor, by locating the ferromagnet inside the permanent magnet, the magnetic field generated by the permanent magnet can be guided and enhanced to the maximum extent. Through this combination, the high magnetic permeability of the ferromagnet and the persistent magnetization characteristics of the permanent magnet can be fully utilized to achieve efficient operation of the electromagnetic device. This paper selects neodymium iron boron for permanent magnet material design, which has good bending strength, compressive strength and thermal expansion coefficient. For the design of the selection of nickel-iron alloy material as the ferromagnetic material, it has extremely high magnetic conductivity and low hysteresis loss. At the same time, in order to better adjust the torque generated by the magnetic field, an excitation power supply is connected to the ferromagnetic excitation coil. The selected inner rotor axial steel body 1302 and inner rotor radial steel body 1301 belong to the soft magnetic material part in the inner rotor. The soft magnetic material plays a very important role in the magnetic circuit, because the permanent magnetic material is installed on the inner and outer rotors of the magnetic coupling transmission. Since the magnetic flux of the inner and outer permanent magnetic materials must pass through the inner and outer rotors to form a loop, the inner and outer rotors must also be made of soft magnetic materials with high magnetic permeability. The use of soft magnetic materials can also prevent interference from the external magnetic field, change the magnetic flux density in the magnetic circuit, and adjust the size of the leakage magnetic flux. The design of selecting silicon steel as the soft magnetic material has high magnetic conductivity, low hysteresis loss, high saturation magnetic induction intensity, and good heat resistance.

As shown in FIG4 , the outer rotor structure is connected to the flexible rod 6 through a keyway. The outer rotor is a disc block and a cylindrical block connected together by bolts. The outer rotor axial magnet 1308 and the outer rotor axial steel body 1309 are embedded in the disc block, and the outer rotor radial steel body 1306 and the outer rotor radial magnet 1307 are embedded in the cylindrical block. As shown in FIG5 and FIG3 , the outer rotor axial magnet 1308 and the outer rotor radial magnet 1307 are made of permanent magnets. Neodymium iron boron is selected as the material for the permanent magnet, which has good bending strength, compressive strength and thermal expansion coefficient. The selected outer rotor axial steel body 1309 and outer rotor radial steel body 1306 belong to the soft magnetic material part of the outer rotor. The soft magnetic material plays a very important role in the magnetic circuit, because the permanent magnetic material is installed on the inner and outer rotors of the magnetic coupling transmission. Since the magnetic flux of the inner and outer permanent magnetic materials must pass through the inner and outer rotors to form a loop, the inner and outer rotors must also be made of soft magnetic materials with high magnetic permeability. The use of soft magnetic materials can also prevent interference from external magnetic fields, change the magnetic flux density in the magnetic circuit, and adjust the size of leakage magnetic flux. This paper selects silicon steel as the design of soft magnetic material, which has high magnetic conductivity, low hysteresis loss, high saturation magnetic induction intensity, and good heat resistance.

The isolation sleeve 1305 in this patent is a double-sealed isolation sleeve. FIG5 is a structural diagram of the isolation sleeve, in which the inner sealing isolation sleeve 130501 is made of metal material (Hastelloy C) and the outer sealing isolation sleeve 130502 is made of ceramic material. The use of this metal-non-metal double-sealed isolation sleeve in a single screw pump has the following advantages: 1 High sealing performance: The metal-non-metal double-sealed isolation sleeve provides higher sealing performance and can effectively prevent pump medium leakage. Because it uses a two-layer sealing structure, namely a double protective layer of metal seal and non-metal seal, it can reduce cross-contamination of media inside and outside the pump body. 2 Reduce maintenance costs: The design of the double-sealed isolation sleeve can reduce the frequency of maintenance and servicing. Metal seals and non-metal seals each have different functions. Once one of the seals fails, the other seal can still keep the pump working normally, reducing the cost of repairing and replacing seals. 3 Improve work efficiency: The metal-non-metal double-sealed isolation sleeve can reduce leakage and medium loss in the pump body and improve the work efficiency of the pump. The installation of the isolation sleeve in the single screw pump is as follows: Because the material of 130501 is different from the material used for the inlet cavity, and the characteristics of the required materials are also different, it is difficult to achieve one-time processing. In order to ensure the high structural strength of the sealing device and the small size of the metal isolation sleeve, 130501 and the inlet cavity are welded. For 130502, it is installed and connected to the inlet cavity at 4 places by bolts. The double seal isolation sleeve made of 1305 double materials can separate the inner rotor from the outer rotor, which plays a sealing role on the pump device and can well combine the characteristics of the two materials to complement each other and work together (metal materials have good process performance, high strength, and small wall thickness, but there is eddy current loss when metal materials are running; ceramic materials can completely eliminate eddy current loss and can also be adapted to almost all corrosive media and high temperature and high wear occasions, but the strength of ceramic materials is limited).

The magnetic circuit design of the magnet is as follows:

As can be seen from FIG6 , the inner rotor radial magnet 1304 is composed of two types of magnetic materials with N-S pole magnetic polarity blocks, namely permanent magnets and ferromagnets. The outer rotor radial magnet 1307 is composed of N-S pole magnetic polarity block magnetic materials made of permanent magnet materials. As can be seen from FIG8 , the inner rotor axial magnet 1303 is obtained by embedding N and S pole magnetic polarity magnetic blocks made of permanent magnet materials and N and S pole magnetic polarity magnetic blocks made of ferromagnetic materials in opposite magnetic arrangement. The outer rotor axial magnet 1308 is configured by magnetic circuits of N and S pole magnetic polarity magnetic blocks made of permanent magnet materials in multiple rows of close arrangement. Because the number of magnetic pole blocks is mostly an even number, the present invention selects a close combination of pull-push arrangement forms with 12 magnetic poles in the magnetic circuit forms of 1304, 1307, 1303, and 1308. FIG10 is a schematic diagram of torque transmission of combined pull-push magnetic circuit, in which the inner rotor is on the upper side and the outer rotor is on the lower side, 1 is a magnet composed of permanent magnet and ferromagnetism at the inner rotor, 2 is a soft magnetic material, F1 is a pulling force, F2 is a thrust force, h is a working gap, and a is a permanent magnet width at the outer rotor. When the magnetic pole S of the outer rotor is located in the middle of the two poles N and S of the inner rotor, the torque is the largest (at this time θ = 90°). According to the principle that like poles repel and opposite poles attract, the forces of the two adjacent magnetic poles on the driven magnetic pole are superimposed in the direction of rotation, which helps to obtain a high transmission torque. At the same time, it can be seen from FIG10 that the axial force can be reduced or even offset by the action of the magnetic field force, which is beneficial to the life of the supporting bearing. It is analyzed that the magnetic coupling transmission sealing device of this magnetic circuit has a non-magnetic metal isolation sleeve between the two magnetic poles. Since the axial magnetic fields generated by the two magnetic poles close to each other offset each other, the eddy current loss in the wall thickness of the isolation sleeve can be effectively controlled or reduced, and the heating of the isolation sleeve caused by the eddy current can also be effectively controlled or reduced. Therefore, the magnetic coupling transmission device of this combined magnetic circuit has a better effect of transmitting energy through the magnetic field through the wall of the device, and is not only suitable for force or torque transmission devices, but also suitable for devices with magnetic coupling transmission sealing structures.

The torque control of magnetic coupling is as follows:

1. Torque calculation at the cylindrical magnetic coupling transmission structure:

FIG7 is a diagram of a cylindrical magnetic coupling transmission structure, which is also a radial magnetic coupling transmission structure. R1 is the radius of the flexible rod (i.e., the driven shaft radius), R2 is the inner radius of the outer rotor radial magnet, R3 is the outer radius of the outer rotor radial magnet, R4 is the inner radius of the inner rotor radial magnet ferromagnet, R5 is the outer radius of the inner rotor radial magnet ferromagnet, the inner radius of the inner rotor radial magnet permanent magnet, R6 is the outer radius of the inner rotor radial magnet permanent magnet, and R7 is the outer radius of the inner rotor radial steel body. t1 is the thickness of the outer rotor radial steel body, t2 is the thickness of the outer rotor radial magnet, t3 is the working gap at the outer rotor, t4 is the thickness of the isolation sleeve, t5 is the working gap at the inner rotor, t6 is the thickness of the inner rotor radial magnet ferromagnet, t7 is the thickness of the inner rotor radial magnet permanent magnet, and t8 is the thickness of the inner rotor radial steel body. f1 is the axial length of the inner rotor radial ferromagnet, the axial length of the inner rotor radial permanent magnet, the axial length of the outer rotor radial magnet, and a is the magnet opening angle.

The magnetic torque is solved by using Gauss's theorem and the B-H curves at the inner and outer rotor permanent magnets. The torque formula is:

Where T1 is the torque, unit is (kgfcm).

K is the magnetic circuit coefficient. Different magnetic circuits have different K values. For the combined push-pull magnetic circuit, K=4~6.4.

M is the magnetization intensity, ( _Bm , _Hm are the magnetic induction intensity and magnetic field intensity of the working point respectively), Gs. _Bm = _Bm1 + _Bm2 , _Hm = _Hm1 + _Hm2 . _Bm1 is the magnetic induction intensity generated by the permanent magnet when it is working, and its value can be measured by using a fluxmeter when the excitation power is turned off. _Hm1 is the magnetic field intensity generated by the permanent magnet magnetic circuit at the outer rotor magnet, Oe, [N ₁ is the empirical coefficient of the pole face shape, and N ₁ = 1.05 for the fan-shaped pole face. t _g is the working air gap width, cm, and in this patent, t _g = t ₃ + t ₄ + t ₅ ; t ₀ is the pole arc length, /> (Outer arc length of the outer rotor magnet pole + inner arc length of the inner rotor magnet permanent magnet pole), cm. η is the magnet thickness coefficient, which is related to _th /t ₀ , and the relationship is shown in Table 1. _th is the magnet thickness, cm, /> _Bm2 is the magnetic induction intensity generated when the excitation power source acts on the ferromagnetic body, and the formula is as follows: _Bm2 = (μ ₀ × N × I) / L, where N is the number of turns of the ferromagnetic coil and L is the length of the ferromagnetic coil. The magnetic field intensity generated by the ferromagnetic body/> Where μ is the magnetic permeability of the ferromagnet.

m is the number of magnetic poles, and m is 12 in the present invention.

S is the pole area of the magnetic pole, cm ² .

R _c is the average rotation radius from the magnetic force acting on the external magnet to the rotation center, cm,

is the displacement angle during operation, °. When/> The torque reaches its maximum value when

When the displacement of the inner and outer magnets is half the width of the magnets in the moving direction, the torque reaches its maximum value, and the axial forces are offset at this time.

The torque generated at the ferromagnet is: T ₂ =x×V×B _m2 , where x is the magnetic susceptibility of the ferromagnet and V is the magnetic volume of the ferromagnet.

The total torque in the cylindrical magnetic coupling device is: T _cylinder = T ₁ + T ₂

Table 1: Relationship between η and t _h /t ₀ (t _h > 0.9)

2. Torque calculation at the disc-shaped magnetic coupling transmission structure:

FIG9 is a diagram of a disc-shaped magnetic coupling transmission structure, which is also an axial magnetic coupling transmission structure. Wherein c1 is the radius at the transmission shaft, c2 is the inner radius of the inner rotor axial magnet, c3 is the outer radius at the inner rotor axial magnet ferromagnet, c4 is the outer radius at the inner rotor axial magnet permanent magnet, and c5 is the outer radius at the inner rotor axial steel body. c6 is the radius at the flexible rod (the radius at the driven shaft), c7 is the inner radius of the outer rotor axial magnet, c8 is the outer radius of the outer rotor axial magnet, and c9 is the outer radius at the outer rotor axial steel body. b1 is the thickness of the inner rotor inner axial steel body, b2 is the thickness of the inner rotor axial magnet ferromagnet, b3 is the thickness of the inner rotor axial magnet permanent magnet, and b4 is the thickness of the inner rotor outer axial steel body. b5 is the thickness of the outer rotor inner axial steel body, b6 is the thickness of the outer rotor axial magnet, and b7 is the thickness of the outer rotor outer axial steel body. k1 is the axial length of the inner rotor axial magnet ferromagnet, the axial length of the inner rotor axial magnet permanent magnet and the axial length of the outer rotor axial magnet, and a is the magnet opening angle.

T3 is the magnetic torque generated by the permanent magnets of the inner and outer rotors:

T ₃ = μ ₀ ** B _m3 * H * D * (Dd) / (4 * π)

Wherein μ ₀ is the magnetic permeability in vacuum (approximately 4π×10 ^-7 N/A ² ), B _m3 is the magnetic induction intensity of the magnetic field, B _m3 = B _m31 + B _m32 . B _m31 is the magnetic induction intensity generated at the permanent magnet, and its measurement method can be the same as measuring the B _m1 value. Its B _m32 is the magnetic induction intensity generated when the excitation power source acts on the ferromagnetic body, and the formula is as follows: B _m32 = (μ ₀ × N × I) / L, where N is the number of turns of the ferromagnetic coil and L is the length of the ferromagnetic coil. H refers to the thickness of the disc-shaped magnetic coupling device, also known as the height, which determines the overall volume of the coupling device and the space to accommodate the magnetic field. D refers to the diameter of the outer circle of the disc-shaped magnetic coupling device, which determines the size of the entire coupling device. d refers to the diameter of the inner circle of the disc-shaped magnetic coupling device.

The torque generated at the ferromagnet is: T ₄ =x×V×B _m32 , where x is the magnetic susceptibility of the ferromagnet and V is the magnetic volume of the ferromagnet.

The total torque in the disc-shaped magnetic coupling device is: _Tdisk = _T3 + _T4

Therefore, the total torque of the total magnetic coupling device is: _Ttotal = _Tcylinder + _Tdisc .

The invention adds a ferromagnetic body and an excitation power source acting on the ferromagnetic body coil to enhance the magnetic field. The torque can be more conveniently controlled by changing the current of the small excitation power source. The magnetic coupling device can achieve smooth torque control.

The change of magnetic field strength in the ferromagnetic body at the magnetic coupling point is as follows:

FIG11 is a detailed diagram of a ferromagnet. Among them, TCT1 is a ferromagnet support frame, TCT2 is an extension port where the ferromagnet support mechanism coil is connected to the power line, TCT3 is a ferromagnet, and TCT4 is a coil. FIG12 is a wiring diagram for connecting the power supply at the ferromagnet. According to the magnetic polarity requirements of the ferromagnets at different installation positions in the radial magnetic coupling device and the axial magnetic coupling device shown in FIG6 and FIG8, TCT3 with different magnetic polarities is installed and placed first. At the ends of the coils wound at the 12 ferromagnets of the axial and radial magnetic coupling devices, the positive and negative poles are connected according to the different required magnetic fields, so that the magnetic polarity of the magnetic field generated around the coil is the same as the magnetic polarity of the ferromagnetic material itself. The power line required to connect to the positive power supply is extended to the same side of TCT2, and the power line required to connect to the negative power supply is extended to the same side of TCT2. The magnetic field strength is affected by changing the magnitude of the power supply current, so as to better realize the change in the torque transmission of the entire magnetic coupling device. Moreover, this design only needs to consider the magnitude change of the current, and no direction change is required. Therefore, the overall structure of the power supply is a DC power supply, a cooling system, and a controller for controlling the current. The value of the required current is derived according to the theoretical formula of the required torque change. Finally, based on the program written to change the current in a certain order, the change of the magnetic field strength at the ferromagnetic coil can be achieved.

The utility model has many advantages by using a magnetic coupling. First, it can improve the transmission efficiency and reliability. The magnetic coupling can transmit the power of the driving end (inner rotor) to the driven end (outer rotor), and drive the movement of the outer rotor to drive the movement of the flexible rod to achieve the transmission of mechanical energy. Moreover, the non-contact transmission of the magnetic coupling can avoid the problems of friction, wear and lubrication, and improve the transmission efficiency and reliability. Second, the power is transmitted through the magnetic field, and the contactless transmission between the drive shaft and the flexible rod is realized. The inlet cavity is installed with the isolation sleeve to form a completely sealed environment at the magnetic coupling device, so that the single-screw pump using the magnetic coupling will not have the problem of seal wear or leakage in the traditional single-screw pump, and the reliability and safety of the pump are improved.

The above is only an explanation of the preferred embodiments of the present invention. The above technical features can be arbitrarily combined to form multiple embodiments of the present invention.

The utility model is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the utility model is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the concept and technical solution of the utility model, or the concept and technical solution of the utility model are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims (8)

1. A new type of magnetic coupling single-screw pump, including a housing, a motor and a magnetic coupling, wherein a stator and a rotor are arranged in the housing, an inlet cavity and an outlet are arranged on the housing, a transmission shaft connected to one end of the rotor is arranged in the inlet cavity, the motor is connected to one end of the transmission shaft through the magnetic coupling, and is characterized in that: the transmission shaft is a flexible rod, and the other end of the flexible rod is connected to one end of the rotor through a flexible coupling. 2. The new magnetically coupled single-screw pump as claimed in claim 1 is characterized in that the rotating shaft of the motor is connected to the magnetic coupler through another coupling. 3. The new magnetically coupled single-screw pump as described in claim 1 is characterized in that: the magnetic coupler includes a magnetic inner rotor structure, a magnetic outer rotor structure and an isolation sleeve, an opening is provided on the shell corresponding to the inlet cavity, the isolation sleeve is arranged at the opening, the magnetic outer rotor structure is located on one side of the isolation sleeve and connected to the end of the flexible rod, and the magnetic inner rotor structure is located on the other side of the isolation sleeve and connected to the rotating shaft of the motor. 4. The novel magnetically coupled single-screw pump as claimed in claim 3 is characterized in that: the isolation sleeve is a cylindrical structure, and the magnetic outer rotor structure is located inside the cylindrical structure. 5. The novel magnetically coupled single-screw pump as claimed in claim 3 is characterized in that the end of the flexible rod is inserted into the magnetic outer rotor structure, and the magnetic outer rotor structure is connected to the end of the flexible rod through a keyway. 6. The new magnetically coupled single-screw pump as described in claim 3 is characterized in that: the shell includes a side shell, an intermediate shell and another side shell connected in sequence, the stator and the rotor are arranged in one side shell, the inlet cavity and the magnetic outer rotor structure are arranged in the intermediate shell, and the magnetic inner rotor structure is arranged in the other side shell. 7. The new magnetically coupled single-screw pump as claimed in claim 3 is characterized in that the isolation sleeve is a double-sealed isolation sleeve, which includes an inner sealing isolation sleeve and an outer sealing isolation sleeve compounded together, the inner sealing isolation sleeve is a metal sleeve, and the outer sealing isolation sleeve is a ceramic sleeve. 8. The new magnetically coupled single-screw pump as described in claim 3 is characterized in that: the magnetic inner rotor structure includes an inner rotor radial steel body and an inner rotor axial steel body, the inner rotor radial steel body is a cylindrical structure with openings at both ends, the inner rotor axial steel body is connected to one end of the cylindrical structure by fasteners, and magnets are provided on the inner rotor radial steel body and the inner rotor axial steel body.