CN103840573B - Stator seal structure of switched reluctance motor - Google Patents

Abstract

The invention discloses a stator sealing structure of a switched reluctance motor, which comprises a stator core, windings surrounding the inner circumference of the stator core, and a casing covering the outside of the stator core; The stator core and the casing, the connection cylinder between the winding and the casing, the stator core, the connection cylinder and the casing surround and form a sealed cavity, and the evaporative cooling liquid is packaged in the sealed cavity, and the The inner wall of the sealed cavity includes the inner wall of the stator core and the inner wall of the connecting cylinder. With this structure, the inner wall of the stator core is not encapsulated, so that the inner wall of the stator core acts as a part of the inner wall of the sealed cavity. Compared with the prior art, the gap between the inner wall of the stator core and the outer surface of the rotor is not occupied, and a smaller gap can still be maintained between the inner surface of the stator core and the outer surface of the rotor. The stator sealing structure can not only reduce vibration and noise, but also avoid the increase of magnetic flux leakage, so as to ensure the working stability of the switched reluctance motor.

Description

Stator sealing structure of a switched reluctance motor

technical field

The invention relates to the technical field of motors, in particular to a stator structure of a switched reluctance motor.

Background technique

Electric vehicles are vehicles driven by electricity that completely replaces petroleum fuels, and have absolute advantages in terms of environmental protection, cleanliness, and energy conservation. The driving motors of electric vehicles mainly include DC motors, asynchronous motors, permanent magnet brushless motors and switched reluctance motors. Switched reluctance motor has become a strong competitor of various drive systems due to its advantages of simple structure, low cost, strong applicability, and wide speed range.

As shown in FIG. 1 , this figure is a schematic structural diagram of a switched reluctance motor in the prior art. When the current control switches SI and S2 of phase A winding 2′ are closed, phase A is energized, while phase B and phase C are not energized, and phase A is excited to generate a magnetic field, because the magnetic flux of the motor is always closed along the path with the smallest reluctance. And when the axis of the magnetic pole of phase A coincides with the axis of the magnetic pole a of the rotor 7', the reluctance of the magnetic circuit is the smallest, so the twisted magnetic field line produces a tangential pulling force, trying to make a-a' coincide with A-A', and finally rotate to a The position where -a' coincides with A-A' stops rotating. Subsequently, if the motor is to be continuously rotated, it is necessary to energize the B phase, and at the same time, the A phase and the C phase are de-energized. At this time, the magnetic field in the motor becomes a magnetic field with the B phase magnetic pole as the axis, and the motor rotor 7' will continue to rotate until coincides exactly with BB'. Then, phase C is energized, and phase A and phase B are de-energized at the same time. At this time, the magnetic field in the motor becomes a magnetic field with the pole axis of phase C, and the motor rotor 7' will continue to rotate until it completely coincides with CC'. Such repeated cycles, as long as the three-phase stator windings 2' are energized in the order of A-B-C-A..., the rotor 7' of the motor will always rotate in the same direction around the center line of the rotating shaft 8'.

It can be seen from the above working process that the electromagnetic torque generated by the switched reluctance motor is not stable like that of traditional AC and DC motors, but pulsating in nature. The corresponding magnetic pull is not only tangential, but also pulsating. There are radial ones, and what pulls the motor to run is the tangential component of the magnetic pull. Because of its pulsating nature, the motor runs unevenly, deforms and vibrates, and generates serious noise. The radial component of the magnetic pulling force will change with the position of the rotor 7' and the current of the stator winding 2', thus causing deformation and vibration of the stator core 1' of the motor, and further generating more serious noise.

For the above problems, as shown in Figure 2, the technology of evaporative cooling has been gradually developed. This technology is to completely seal the entire stator in a cavity, which is injected with low boiling point, high insulation, non-combustible evaporative cooling fluid 6'. When the motor is running, the winding 2', stator core 1', and other structural components generate a lot of heat due to various losses, so that the temperature of the evaporative cooling liquid 6' filled around it rises until it reaches the pressure in the cavity. The corresponding saturation temperature of the liquid medium begins to boil, and then absorbs heat and vaporizes, forming a gas-liquid two-phase state, so that the heating parts can be fully cooled, and because the temperature of the boiling working medium during the boiling heat exchange is basically distributed near the saturation temperature point, The temperature distribution of each stator part immersed in the medium is relatively uniform, especially there is no local hot spot at the end of the stator. The steam coolant in the gas-liquid two-phase state has a density lower than that of the liquid medium, which generates buoyancy and rises up to meet the condenser 9' at the top, transfers heat to the condensed water in it, condenses into a liquid and drops back to the original state In this way, self-circulation and noiseless evaporative cooling are realized at room temperature.

Since the stator is the main part that emits vibration and noise, and the stator is soaked in insulating liquid, the liquid will form a great frictional resistance to any movement trend of the stator, which will damp and attenuate the vibration of the stator, and will also prevent the transmission of sound , so the effect of vibration reduction and noise reduction is obvious.

As shown in Figure 2, the above-mentioned evaporative cooling technology uses a sleeve 4' to be closely attached to the inner surface of the stator core 1', and the two ends of the sleeve 4' are connected with the shell 3' of the switched reluctance motor, and the The entire stator that needs to be cooled (including all stator cores 1' and windings 2') is completely surrounded to form a sealed cavity, and then the evaporative cooling liquid 6' is injected into the sealed cavity to make the evaporative cooling liquid 6' The stator core 1' and windings 2' are soaked. As shown in Figure 3 and Figure 4, Figure 3 and Figure 4 are the front sectional view and side sectional view of the sealing cylinder in Figure 2 respectively, the sleeve 4' is a cylindrical integral sleeve 4' with openings at both ends, In this way, the gap (referred to as "air gap" in electromechanical science) between the stator and the rotor 7' must be made large enough to put down the sleeve 4' (generally requiring the air gap to be at least 3mm), and This structural principle is not applicable to switched reluctance motors. Because the switched reluctance motor uses the change rate of the main magnetic flux (also called reluctance) between the stator and rotor 7' to generate the electromagnetic torque that drives the motor to rotate. If the air gap is too large, it will cause the main magnetic flux and the main magnetic flux The rate of change of flux decreases while the leakage flux increases, thereby weakening the drive torque and increasing noise.

In view of this, it is urgent to address the above technical problems and further optimize the design of the stator sealing structure of the existing switched reluctance motor so that it can eliminate the vibration and noise generated by the stator core without occupying the stator and rotor. The air gap between them avoids the increase of magnetic flux leakage and enhances the working stability of the switched reluctance motor.

Contents of the invention

The purpose of the present invention is to provide a stator sealing structure of a switched reluctance motor, the inner wall of the sealed chamber of the structure includes the inner wall of the stator core, that is, the connecting cylinder connecting the housing and the stator core does not occupy the space between the stator and the rotor. Space, not only eliminates the vibration and noise generated by the stator core, but also avoids the increase of magnetic flux leakage, and enhances the working stability of the switched reluctance motor.

In order to solve the above-mentioned technical problems, the present invention provides a stator sealing structure of a switched reluctance motor, which includes a stator core, windings surrounding the inner circumference of the stator core, and a casing that covers the outside of the stator core; It includes a connecting cylinder axially connecting the stator core and the housing, the winding and the housing, the connecting cylinder encloses the winding from the inside, the stator core, the connecting cylinder and the housing Surrounding forms a sealed cavity, the sealed cavity encapsulates evaporative cooling liquid, and the inner wall of the sealed cavity includes the inner wall of the stator core and the inner wall of the connecting cylinder.

With this structure, the connecting cylinder connects the axial space between the stator core and the casing, the axial space between the winding and the casing, and the inner wall of the sealed cavity includes the inner wall of the stator core and the inner wall of the connecting cylinder, so , the inner wall of the stator core is not encapsulated, so that the inner wall of the stator core acts as a part of the inner wall of the sealed cavity. Compared with the prior art, the gap between the inner wall of the stator core and the outer surface of the rotor is not occupied, and a small gap (usually not more than 0.4mm) can still be maintained between the inner surface of the stator core and the outer surface of the rotor ). It can be seen that the stator sealing structure can not only reduce vibration and noise, but also avoid the increase of magnetic flux leakage and ensure the working stability of the switched reluctance motor.

Preferably, the connecting cylinder includes two identical half-tube structures, each half-tube structure includes arc-shaped connecting plates having the same number as the stator core, and each connecting plate includes a press-fit section and a connecting section; The press-fit section is press-fit on the inner side of the winding, and every two adjacent press-fit sections form a groove for accommodating the stator core; a plurality of the connecting sections are connected end to end to form a ring structure, and the The annular structure is connected to the housing, and the press-fit sections of the two half-cylinder structures are butted to form the connecting cylinder.

Preferably, in the cross section of the switched reluctance motor, the inner surface of the press-fit section and the inner surface of the stator core are on the same circular arc centered on the center of the rotating shaft of the switched reluctance motor .

Preferably, the connecting sections of every two adjacent connecting plates are butted end-to-end to form the annular structure, and each of the connecting plates is connected to the housing.

Preferably, the connecting sections of every two adjacent connecting plates are overlapped end to end to form the ring structure, and every two connecting plates are connected to the housing at the overlapped portion.

Preferably, both ends of the connecting sections arranged alternately in the ring structure are provided with bent parts, and the bent parts overlap with the adjacent connecting sections.

Preferably, the connecting plate is provided with a first positioning hole, the housing includes an end cover and a fixing cylinder provided on one side of the end cover, and the fixing cylinder is provided with a corresponding to the first positioning hole. The second positioning hole, the fixing cylinder and the annular structure are connected by threaded fasteners inserted in the first positioning hole and the second positioning hole.

Description of drawings

Figure 1 is a schematic diagram of the structure of the switched reluctance motor;

Fig. 2 is a schematic diagram of a stator sealing structure of a switched reluctance motor in the prior art;

Fig. 3 and Fig. 4 are the front sectional view and the side sectional view of the sealing cylinder in Fig. 2 respectively;

Fig. 5 is a schematic diagram of the stator sealing structure of the switched reluctance motor provided by the present invention;

Fig. 6 is a cross-sectional view of the stator sealing structure shown in Fig. 5;

Fig. 7 is a perspective view of a specific embodiment of the half-cylinder structure of the connecting cylinder in Fig. 6;

Fig. 8 is a schematic structural view of the connecting plate in Fig. 7;

Fig. 9 is a perspective view of another specific embodiment of the half-cylinder structure of the connecting cylinder in Fig. 6;

Fig. 10 and Fig. 11 are the front view and side view of the casing of the switched reluctance motor provided by the present invention.

Wherein, the corresponding relationship between the reference numerals and the part names in Fig. 1 to Fig. 4 is:

Stator core 1'; winding 2'; shell 3'; sleeve 4'; evaporative cooling liquid 6'; rotor 7'; shaft 8'; condenser 9';

The corresponding relationship between the reference numerals and the part names in Fig. 5 to Fig. 11 is:

Stator core 1;

Winding 2;

Housing 3; end cap 31; fixing cylinder 32; second positioning hole 321;

Connecting cylinder 4; Half cylinder structure 4a; Connecting plate 41; Press-fit section 411; Connecting section 412;

Sealing chamber 5; evaporative coolant 6; rotor core 7; rotating shaft 8; condenser 9.

detailed description

The core of the present invention is to provide a stator sealing structure of a switched reluctance motor. This structure does not seal the inner wall of the stator core, which can not only eliminate the vibration and noise generated by the stator core, but also not occupy the space between the stator and the rotor. The air gap avoids the increase of magnetic flux leakage and enhances the working stability of the switched reluctance motor.

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

It should be noted that the orientation word "axial" in this article refers to the direction in which the axis of the main shaft on which the rotor is installed extends, that is, the direction extending left and right in Figure 5; The direction in which the axis spreads radially outwards, that is, the direction in which the axis spreads outwards from the center of the circle in Figure 6; the orientation word "inside" is the opposite. It should be understood that these orientation words are established based on the drawings in the specification, and their appearance should not affect the protection scope of the present invention.

Please refer to FIG. 5 and FIG. 6. FIG. 5 is a schematic diagram of the stator sealing structure of the switched reluctance motor provided by the present invention; FIG. 6 is a cross-sectional view of the stator sealing structure shown in FIG. 5 .

In a specific embodiment, as shown in Figure 5 and Figure 6, the present invention provides a stator sealing structure of a switched reluctance motor, comprising a stator core 1 and a winding 2 surrounding the inner circumference of the stator core 1, and The casing 3 covered outside the stator core 1 also includes a connecting cylinder 4 axially connecting the stator core 1 and the casing 3, the winding 2 and the casing 3, the connecting cylinder 4 encloses the winding 2 from the inside, and the stator core 1. The connecting cylinder 4 and the housing 3 surround and form a sealed cavity 5 , which encapsulates the evaporative cooling liquid 6 , and the inner wall of the sealed cavity 5 includes the inner wall of the stator core 1 and the inner wall of the connecting cylinder 4 . The rotor structure of the above-mentioned switched reluctance motor includes a rotating shaft 8 and a rotor 7 connected to the rotating shaft 8 , and a gap is provided between the stator core 1 and the rotor 7 .

With this structure, the connecting cylinder 4 connects the axial space between the stator core 1 and the housing 3, the axial space between the winding 2 and the housing 3, and the inner wall of the sealed cavity 5 includes the inner wall of the stator core 1 and the inner wall of the connecting cylinder 4 , therefore, the inner wall of the stator core 1 is not encapsulated, so that the inner wall of the stator core 1 serves as a part of the inner wall of the sealed cavity 5 . Compared with the prior art, the gap between the inner wall of the stator core 1 and the outer surface of the rotor 7 is not occupied, and a smaller gap (usually not exceeding 0.4mm). It can be seen that the stator sealing structure can not only reduce vibration and noise, but also avoid the increase of magnetic flux leakage and ensure the working stability of the switched reluctance motor.

Please refer to FIG. 7 and FIG. 8 , FIG. 7 is a perspective view of a specific embodiment of the connecting cylinder 4 in FIG. 6 ; FIG. 8 is a schematic structural diagram of the connecting plate 41 in FIG. 7 .

In a specific solution, as shown in Fig. 7 and Fig. 8, the connecting cylinder 4 includes two identical semi-cylindrical structures 4a, and each semi-cylindrical structure 4a includes arc-shaped connecting plates 41 having the same number as the stator core 1, each A connecting plate 41 includes a press-fit section 411 and a connecting section 412; the press-fit section 411 is press-fitted on the inner side of the winding 2, and every two adjacent press-fit sections 411 form a groove 42 for accommodating the stator core 1; multiple connections The segments 412 are connected end to end to form a ring structure, and the ring structure is connected to the housing 3 , and the press-fit segments 411 of the two half-tube structures 4 a are butted to form the connecting tube 4 .

With this structure, during the installation process, insert the two semi-cylindrical structures 4a from both ends of the stator core 1 axially to the middle, so that the press-fit section 411 of each arc-shaped connecting plate 41 is press-fitted on the On the inner side of the winding 2, the two half-tube structures 4a are butted to form the connecting tube 4, and then the connecting section 412 of the connecting plate 41 is connected to the housing 3, and finally the packaging of the stator sealing structure is completed.

In this way, the press-fit section 411 of the arc-shaped connecting plate 41 plays the role of sealing the winding 2, and the groove 42 formed between every two adjacent press-fit sections 411 is used to accommodate the stator core 1, and the arc-shaped connecting plate The connecting cylinder 4 formed by connecting the connecting section 412 of 41 is set in the axial space between the end of the stator core 1 and the housing 3 , and between the winding 2 and the housing 3 to play the role of axial connection. The connecting cylinder 4 with this structure can realize the axial connection between the stator core 1 and the casing 3 and the axial connection between the winding 2 and the casing 3 simply and conveniently.

It should be noted that the above-mentioned connecting cylinder 4 is not limited to include two semi-cylindrical structures, but can also be set as an integrated structure, and the connecting cylinder 4 can be inserted from one side of the stator core 1 during installation.

In a further solution, as shown in FIG. 6, in the cross-section of the switched reluctance motor, the inner surface of the press-fit section 411 and the inner surface of the stator core 1 are at the same center with the center of the rotating shaft 8 of the switched reluctance motor. on the arc.

Since the press-fit section 411 of the connecting plate 41 and the inner surface of the stator core 1 jointly form the inner surface of the sealed cavity 5, the above-mentioned structure makes the distance from the inner wall of the entire sealed cavity 5 to the center of the rotating shaft 8 the same, which is convenient for subsequent packaging work. It also makes the structure of the switched reluctance motor symmetrical, further reducing vibration and noise. Compared with the sealed stator structure in which the press-fit section 411 is arranged outside the inner surface of the stator core 1, this structure can maximize the volume in the sealed cavity 5, so as to accommodate more evaporative cooling fluid 6, and further reduce the switching reluctance Motor vibration and noise.

The specific connection manner of the connecting cylinder 4 can also be further set.

In a specific embodiment, the connection segments 412 of each adjacent two connection plates 41 are butted end to end to form a ring structure, and each connection plate 41 is connected to the housing 3 .

With this structure, the structure of the connecting cylinder 4 is simple and symmetrical, and the installation and disassembly of each connecting plate 41 is convenient.

It is conceivable that the above-mentioned connecting cylinder 4 is not limited to the above-mentioned structure.

In another specific embodiment, as shown in FIG. 9, FIG. 9 is a perspective view of another specific embodiment of the connecting cylinder 4 in FIG. structure, and every two connecting plates 41 are connected to the housing 3 at the overlapping portion. With this structure, the housing 3 is connected to multiple connecting plates 41 at the same time, and every two adjacent connecting plates 41 are also connected, which can enhance the reliability of the connection between the connecting cylinder 4 and the housing 3 .

In the specific solution, as shown in Figure 9, the two ends of the connecting sections 412 (for example, the first, third and fifth of the six connecting plates 41) arranged alternately are provided with outward bending parts 4122, and the rest are arranged alternately. The connection plates 41 (for example, the second, fourth, and sixth of the six connection plates 41 ) are normally arranged, and the bent portion 4122 is overlapped with the adjacent connection section 412 .

It is conceivable that the manner in which two adjacent connecting plates 41 are overlapped is not limited to this one. For example, one end of the connecting section 412 of each arc-shaped connecting plate 41 may be provided with the above-mentioned bent portion 4122, and the other end may be provided normally. In every two adjacent connecting plates 41 , one end of one connecting plate 41 with the bent portion 4122 overlaps with the other end of the other connecting plate 41 without the bent portion, so that the two end-to-end overlap.

The specific connection manner between the above-mentioned connecting cylinder 4 and the housing 3 can also be further set.

In another specific embodiment, as shown in Figure 10 and Figure 11, Figure 10 and Figure 11 are the front view and side view of the casing of the switched reluctance motor provided by the present invention, and the connecting plate 41 may be provided with The first positioning hole 4121, the housing 3 includes an end cover 31 and a fixing cylinder 32 located on one side of the end cover 31, the fixing cylinder 32 is provided with a second positioning hole 321 corresponding to the first positioning hole 4121, the fixing cylinder 32 and the ring The structures are connected by threaded fasteners inserted into the first positioning hole 4121 and the second positioning hole 321 .

With this structure, the connection between the annular structure and the connecting cylinder 4 of the casing 3 can be realized simply and conveniently, and the connection reliability of the two is relatively strong. It is conceivable that the connection between the shell 3 and the ring structure is not limited to threaded fasteners, and other ways can also be used, for example, a ring groove that fits with the ring structure can be provided in the fixing cylinder 32 of the shell 3 . When one side of each connecting plate 41 of the ring structure is press-fitted on the inner side of the winding 2 and the other side forms a ring structure, the ring structure can be interference-fitted into the ring groove, and a stable connection between the two can also be realized.

The stator sealing structure of a switched reluctance motor provided by the present invention has been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention, and the descriptions of the above embodiments are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (6)

1. A stator sealing structure of a switched reluctance motor, comprising a stator core (1), a winding (2) surrounding the inner circumference of the stator core (1), covered outside the stator core (1) The casing (3); is characterized in that it also includes a connecting cylinder that axially connects the stator core (1) and the casing (3), the winding (2) and the casing (3) (4), the connecting cylinder (4) encapsulates the winding (2) from the inside, and the stator core (1), the connecting cylinder (4) and the casing (3) surround and form a sealed cavity (5), The evaporative cooling liquid (6) is encapsulated in the sealed cavity, and the inner wall of the sealed cavity (5) includes the inner wall of the stator core (1) and the inner wall of the connecting cylinder (4); the connecting cylinder (4) ) includes two identical semi-tube structures (4a), Each semi-cylindrical structure (4a) includes arc-shaped connecting plates (41) with the same number as the stator core (1), and each connecting plate (41) includes a press-fit section (411) and a connecting section (412 ); the press-fitting section (411) is press-fitted on the inner side of the winding (2), and every two adjacent press-fitting sections (411) form a groove for accommodating the stator core (1) ( 42); a plurality of connecting segments (412) are connected end to end to form an annular structure, and the annular structure is connected to the housing (3), The press-fit sections (411) of the two half-tube structures (4a) are butted to form the connecting tube (4). 2. The stator sealing structure of the switched reluctance motor according to claim 1, characterized in that, in the cross section of the switched reluctance motor, the inner surface of the press-fit section (411) is in contact with the stator iron The inner surface of the core (1) is on the same circular arc with the center of the rotating shaft (8) of the switched reluctance motor as the center. 3. The stator sealing structure of switched reluctance motor according to claim 2, characterized in that, the connecting sections (412) of every two adjacent connecting plates (41) are butted end-to-end to form the ring structure, and each Each of the connecting plates (41) is connected to the housing (3). 4. The stator sealing structure of the switched reluctance motor according to claim 2, characterized in that, the connecting segments (412) of every two adjacent connecting plates (41) overlap end to end to form the ring structure, and each The two connecting plates (41) are connected to the casing (3) at overlapping portions. 5. The stator sealing structure of switched reluctance motor according to claim 4, characterized in that, the two ends of the connecting sections (412) arranged alternately in the annular structure are provided with bent parts (4122), so The bending portion (4122) overlaps with the adjacent connecting section (412). 6. The stator sealing structure of the switched reluctance motor according to any one of claims 1-5, characterized in that, the connecting plate (41) is provided with a first positioning hole (4121), and the housing ( 3) It includes an end cover (31) and a fixing cylinder (32) arranged on one side of the end cover (31), and the fixing cylinder (32) is provided with a second corresponding to the first positioning hole (4121). The positioning hole (321), the fixing cylinder (32) and the annular structure are connected by threaded fasteners inserted in the first positioning hole (4121) and the second positioning hole (321).