CN111490660A - Single-phase rotary proportional electromagnet based on hybrid air gap - Google Patents

Abstract

A one-way rotating electromagnet based on a mixed air gap, the front and rear sides of the stator are respectively installed with a front end cover and a rear end cover, a rotor is installed in the stator, an output shaft is installed on the rotor, and the output shaft is connected with a reset torsion spring; the stator It consists of a front stator and a rear stator. The front stator and the rear stator ring are evenly distributed with N stator poles around the circumference. The front stator and the rear stator are respectively provided with symmetrical grooves along the interface, which are assembled to form an annular groove. The annular groove is placed with a control coil to form Control the magnetic flux; the rotor is evenly distributed with N toothed rotor magnetic poles along the radial direction, each rotor magnetic pole face is composed of two parts, the first part is a circular arc annular surface, which forms a radial air gap with the stator magnetic poles; the second The part is a rectangular surface, which is located at the end of the tooth surface and forms an axial air gap with the side faces of the stator poles. The present invention can obtain a near-horizontal moment-angle characteristic curve.

Description

Single-phase rotary proportional electromagnet based on hybrid air gap

technical field

The invention relates to a rotary proportional electromagnet.

Background technique

The rotary valve is a kind of reversing valve that uses the rotary motion to change the relative position of the valve core and the valve sleeve, so as to change the flow path inside the rotary valve, and finally realize the opening and closing or reversing of the flow path. Rotary valves can be driven manually, mechanically or directly by motors, motors and rotating electromagnets for precise servo/proportional control. Compared with spool valve or poppet valve, rotary valve has the advantages of high reliability, simple structure, high working frequency, and strong resistance to oil pollution. It can be widely used in hydraulic systems of high-speed switching, high-speed excitation and high-speed reversing. , especially when the number of throttle grooves of the spool valve sleeve is large, the single-stage rotary valve can obtain a larger rated flow than the multi-stage spool valve. However, in the existing electro-hydraulic servo/proportional control system, the application of rotary valve is far less extensive than that of slide valve. The reasons are: first, the processing of the throttle groove/window of the rotary valve is more complicated, and the second is that the rotary electromagnet used to drive the rotary valve is much more difficult to obtain proportional control characteristics than the direct-acting proportional electromagnet. Magnetic ring structure, the magnetic circuit is divided into two axial and radial paths at the magnetic isolation ring during excitation, and the horizontal stroke-thrust characteristics required by proportional control can be obtained after synthesis. It is not a big problem in mass automated production, and the rotating electromagnet often needs to be specially optimized for the shape of the stator teeth and rotor teeth to obtain a relatively flat torque-angle characteristic, which greatly limits its practical application.

In order to popularize and apply rotary valves in electro-hydraulic servo/proportional systems, a lot of research has been done on the optimization of the magnetic circuit topology and moment-angle characteristics of rotating electromagnets. Torque motors, which are widely used in nozzle flapper valves and jet tube servo valves, can also obtain proportional position control characteristics through reasonable design of elastic elements. However, because their magnetic circuits are based on axial air gaps, it is difficult to obtain large working angle. The improved torque motor based on the radial working air gap proposed by Montagu of General Inspection Company of the United States further expands its working angle range, and it has positive electromagnetic stiffness, which can obtain proportional position control characteristics without adding elastic elements. . In order to obtain a flat moment-angle characteristic curve, Hitachi's Fumio specially designed the shape of the permanent magnets on the rotor of the moving magnet torque motor. This compensates for the torque ripple associated with the rotation of the rotor. The permanent magnet torque motor designed by Jiro Jinto of Denso Company in Japan, the two magnetic poles composed of discrete permanent magnets are asymmetrically arranged on the outside of the rotating shaft with a difference of half the magnetic pole angle, so as to compensate for the outer circumference of the polygonal magnetic poles. Torque pulsation to obtain smooth torque-angle characteristics. The electric excitation torque motor developed by Zhang Guangqiong of Zhejiang University and others specially designed the shapes of the stator poles and rotor pole faces, and changed the torque angle characteristics of the motor by controlling the magnetic flux saturation at the tip of the stator pole shoe. Cui Jian et al. proposed a dynamic magnetic rotary proportional electromagnet based on a radial working air gap, which is based on a differential magnetic circuit and has positive electromagnetic stiffness, but its structure is complex, which is not conducive to industrial application and large-scale mass production.

SUMMARY OF THE INVENTION

In order to overcome the disadvantages of the existing rotating electromagnets, such as difficulty in obtaining horizontal torque-angle characteristics, complex structure, and unfavorable industrial application and large-scale mass production, the present invention provides a hybrid air-gap based hybrid air gap with horizontal torque-angle characteristics. , Simple structure of one-way rotating electromagnet.

The basic principle of the invention is as follows: the commonly used working air gaps in rotary electro-mechanical converters include radial air gaps and axial air gaps. With the increase of (the stator and rotor are gradually aligned), the output torque will decrease, that is, the slope of its moment-angle characteristic curve is negative; while the axial air gap has a narrow working range, but the output torque increases with the increase of the misalignment angle, that is, its The slope of the moment-angle characteristic curve is positive. Therefore, the working air gap of the present invention is divided into two parts, the main working air gap is a radial air gap, and an axial air gap is added on the basis of the radial air gap. The torques generated by the radial air gap and the axial air gap are mutually modulated. After reasonable parameter optimization, a near-horizontal moment-angle characteristic curve can be obtained, and a proportional position control characteristic can be obtained by adding a return torsion spring.

The technical scheme adopted by the present invention to solve its technical problems is:

A unidirectional rotating electromagnet based on a mixed air gap, the front and rear sides of the stator are respectively installed with a front end cover 1 and a rear end cover 5, a rotor 7 is installed in the stator, an output shaft 6 is installed on the rotor 7, and the output shaft 6 is connected to the reset torque. Spring 4. The stator is composed of a front stator 2 and a rear stator 3, and N stator magnetic poles 21 are evenly distributed around the circumference of the front stator 2 and the rear stator 3, which is beneficial to increase the output torque. The front stator 2 and the rear stator 3 are respectively provided with symmetrical grooves along the interface, which are assembled to form an annular groove 22, and the annular groove 22 is placed with the control coil 8 to form a control magnetic flux.

The rotor 7 has N toothed rotor magnetic poles evenly distributed in the radial direction, and each rotor magnetic pole face consists of two parts. The second part is a rectangular surface 72 , which is located at the end of the tooth surface and forms an axial air gap with the side surface of the stator magnetic pole 21 .

Preferably, the return torsion spring 4 includes a spring 41 , a spring cover 42 and a coupling 43 , the spring cover 42 is connected to the rear end cover 5 , the spring 41 is installed on the spring cover 42 , and the coupling 43 is installed on the spring 41 , the rear end of the output shaft 6 is fixed in the central hole of the coupling 43 . The output shaft 6 is fixed on the rotor 7 . When the rotary torque motor rotates clockwise and counterclockwise, since the torque motor does not have spring stiffness characteristics, an external return torsion spring 4 is required to return the rotor 7 to the neutral position.

Preferably, the front stator 2 and the rear stator 3 have 8 stator poles evenly distributed around the circumference, and each stator pole is separated by 45°, and the rotor 7 has 8 tooth-shaped rotor poles evenly distributed along the radial direction.

Preferably, the rotor 7 adopts a hollow cup structure, which reduces the moment of inertia and is beneficial to increase the response speed. The front end cover 2, the rear end cover 5 and the output shaft 6 are made of non-magnetic metal material, while the rotor 7, the front stator 2 and the rear stator 3 are made of high magnetic permeability metal soft magnetic material.

The beneficial effects of the present invention are mainly manifested in:

1. The hybrid working air gap is used to obtain horizontal torque-rotation angle characteristics. The working air gap of the present invention is divided into two parts, the main working air gap is a radial air gap, and an axial air gap is added on the basis of the radial air gap. The torques generated by the radial air gap and the axial air gap are mutually modulated. After reasonable parameter optimization, a near-horizontal moment-angle characteristic curve can be obtained, and a proportional position control characteristic can be obtained by adding a return torsion spring.

2. Fast response speed and large output torque. Compared with the cylindrical structure of other rotary proportional electromagnet rotors, the rotor of the solution provided by the present invention has a hollow cup structure, and the moment of inertia is small, which is beneficial to obtain a higher dynamic response speed. The multi-pole structure design is beneficial to improve the output torque.

3. Using single coil excitation, the control is simple. Compared with the dual-phase excitation structure, the single-coil excitation can effectively reduce the complexity of the drive circuit, and the control is simpler.

4. Simple structure and low cost. Compared with other rotary proportional electromagnets, the solution provided by the present invention has fewer parts, easy processing and assembly, and low manufacturing cost, which is beneficial to practical industrial application and mass production.

Description of drawings

Fig. 1 is the schematic diagram of the present invention;

Fig. 2 is the assembly schematic diagram of the present invention

Fig. 3 is the stator structure schematic diagram of the present invention;

Fig. 4 is the rear end cover structure schematic diagram of the present invention;

Fig. 5 is the structure schematic diagram of the reset torsion spring of the present invention;

Fig. 6 is the front end cover structure schematic diagram of the present invention;

Fig. 7 is the output shaft structure schematic diagram of the present invention;

Fig. 8 is the rotor structure schematic diagram of the present invention;

FIG. 9 is a schematic diagram of moment-angle characteristic curves of radial air gap, axial air gap and mixed air gap;

FIG. 10 is a schematic diagram of the structural principle of the present invention.

FIG. 11 is a schematic diagram of the working principle of the present invention, and the control coil is fed with a forward current.

FIG. 12 is a schematic diagram of the working principle of the present invention, and the control coil is fed with a reverse current.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings.

1 to 8, a unidirectional rotating electromagnet based on a mixed air gap, the front and rear sides of the stator are respectively installed with a front end cover 1 and a rear end cover 5, a rotor 7 is installed in the stator, and an output shaft 6 is installed on the rotor 7 , the output shaft 6 is connected to the return torsion spring 4 .

The stator of the present invention is composed of a front stator 2 and a rear stator 3. Each stator has 8 stator magnetic poles 21, and each stator magnetic pole 21 is separated by 45° and distributed on the circumference, which is beneficial to improve the output torque. The front stator 2 and the rear stator 3 are respectively provided with symmetrical grooves along the interface to form an annular groove 22, and a control coil 8 is placed in the annular groove to form a control magnetic flux.

The rotor component is composed of an output shaft 6 and a rotor 7. The rotor 7 is evenly distributed with 8 toothed rotor magnetic poles along the radial direction. The tooth end face of each rotor magnetic pole is composed of two parts. The first part 71 is an arc annular surface. , which forms a radial air gap with the radial end face of the stator magnetic pole 21 . The second portion 72 is a rectangular surface, which is located at the end of the tooth end surface and forms an axial air gap with the side surface of the stator magnetic pole 21 . The front end cover 1 , the rear end cover 5 and the output shaft 6 are made of non-magnetic metal material, while the rotor 7 and the front stator 2 and the rear stator 3 are made of high magnetic permeability metal soft magnetic material.

The return torsion spring includes a spring 41, a spring cover 42, a coupling 43, the spring cover 42 is connected to the rear end cover 5, the spring 41 is installed on the spring cover 42, the coupling 43 is installed on the spring 41, and the output The rear end of the shaft 6 is fixed in the central hole of the coupling 43 . The output shaft 6 is fixed on the rotor 7 . When the rotary torque motor rotates clockwise and counterclockwise, since the torque motor does not have spring stiffness characteristics, an external return torsion spring 4 is required to return the rotor 7 to the neutral position.

As shown in FIG. 10 , when the control coil 8 is not energized, there is no magnetic flux in the air gap, and under the action of the return torsion spring 4 , the rotor 7 is in the initial position of the neutral position.

When the control coil 8 is supplied with the current as shown in Fig. 11 and Fig. 12, the control coil 8 generates a control magnetic flux, and the rotor 7 rotates clockwise under the action of the electromagnetic torque. The torque is modulated with each other, so that the electromagnet can obtain a nearly horizontal moment-angle characteristic. The magnitude of the output torque can be adjusted by controlling the magnitude of the current. When used with a linear spring, the position control effect proportional to the current can be obtained.

The content described in the embodiments of the present specification is only an enumeration of the realization forms of the inventive concept, and the protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments, and the protection scope of the present invention also extends to those skilled in the art. Equivalent technical means that can be conceived by a person based on the inventive concept.

Claims (4)

1. A one-way rotating electromagnet based on a mixed air gap, characterized in that: the front and rear sides of the stator are respectively installed with a front end cover (1), a rear end cover (5), a rotor (7) is installed in the stator, and the rotor ( 7) An output shaft (6) is installed on it, and the output shaft (6) is connected to the reset torsion spring (4); the stator is composed of a front stator (2) and a rear stator (3), and the front stator (2) and the rear stator ( 3) N stator magnetic poles (21) are evenly distributed around the circumference; the front stator (2) and the rear stator (3) are respectively provided with symmetrical grooves along the interface, which are assembled to form an annular groove (22), and the annular groove (22) is placed a control coil (8) to form a control magnetic flux; The rotor (7) is uniformly distributed with N toothed rotor magnetic poles in the radial direction, and each rotor magnetic pole face consists of two parts, the first part is an arc annular surface (71), which forms a radial direction with the stator magnetic poles (21). Air gap; the second part is a rectangular surface (72), which is located at the end of the tooth surface and forms an axial air gap with the side surface of the stator magnetic pole (21). 2. The one-way rotating electromagnet based on a hybrid air gap according to claim 1, wherein the return torsion spring (4) comprises a spring (41), a spring cover (42), a coupling (43) ), the spring cover (42) is connected to the rear end cover (5), the spring (41) is mounted on the spring cover (42), the coupling (43) is mounted on the spring (41), the output shaft (6) is The rear end is fixed in the center hole of the coupling (43). The output shaft (6) is fixed on the rotor (7). 3. A kind of unidirectional rotating electromagnet based on mixed air gap as claimed in claim 1 or 2, it is characterized in that: 8 stator magnetic poles (21) uniformly distributed on the circumference of front stator (2) and rear stator (3) ), each stator pole (21) is separated by 45°, and the rotor (7) has 8 tooth-shaped rotor poles evenly distributed along the radial direction. 4. A unidirectional rotating electromagnet based on a mixed air gap as claimed in claim 3, characterized in that: the rotor (7) adopts a hollow cup structure; the front end cover (2) and the rear end cover (5) and the output The shaft (6) is made of a non-magnetic metal material, and the rotor (7), the front stator (2), and the rear stator (3) are made of a metal soft magnetic material with high magnetic permeability.

Images