CN111900816A - Scattered wire winding motor - Google Patents

Abstract

The invention discloses a loose-wire winding motor, which belongs to the technical field of motors, wherein when two stator coils are connected in series, transposition is performed according to the inductance of the parallel-wound conductors, so that the inductance difference between M series conductors obtained in series is minimized; At the end where the outgoing terminal is located, a wiring board is also fixed. The wiring board is located between the stator and the end cover and is in close contact with the end of the stator coil; the wiring board includes a fixing ring and a plurality of The junction box, the junction box is provided with a circumferentially open wiring slot, and the wiring slot is provided with a wiring copper bar; the wiring copper bar is placed in a stepped shape along the axial direction; the peripheral outer surface of the junction box is provided with heat dissipation ribs; stator coils The M parallel-wound conductors are arranged in a manner that minimizes the layers of the parallel-wound conductors in the stator coil along the slot depth direction; the stator slot is provided with a larger arched slot wedge. The invention can effectively reduce the circulating current between the parallel winding conductors in the scattered wire winding motor, and suppress the AC copper loss.

Description

A loose wire winding motor

technical field

The invention belongs to the technical field of motors, and more particularly, relates to a loose-wire winding motor.

Background technique

Due to its advantages in efficiency, power density and high reliability, permanent magnet motors are being widely used in new energy-related industries to promote the development of a new round of electrification. The scattered wire winding motor is embedded in the stator slot of the permanent magnet motor along the radial direction by one or more parallel winding wires, forming a multi-turn structure around the stator teeth to act as a motor coil as an energy exchange with the rotor magnetic field. The medium, because of its simple and reliable processing technology and low manufacturing cost, is widely used in the field of motors, especially commercial motors.

The traditional off-line process applied to the scattered-wire winding motor is highly arbitrary, ignoring the shaping and layout of the conductor arrangement, which makes the position of the winding wire of the scattered-wire winding motor uncertain, so that the copper consumption is too large. It will bring a severe test to the overall thermal safety of the motor. When the coils are connected in series, the AC copper loss in the motor can be improved by transposition. In high-power flat wire motors, the transposition method is often used. Since the flat wire motors are usually formed windings, the shape of the coils is fixed when they are offline. When the end is twisted 180 degrees, so as to achieve transposition.

However, since the conductors of the loose-wire motor are messy in the down-line, it is difficult to ensure a significant effect by twisting the ends by 180 degrees. Therefore, this transposition method applied to the high-power flat-wire motor is used in the loose-wire motor. Rarely, when applied to a loose-wire motor, it cannot achieve a good effect of suppressing AC copper loss.

SUMMARY OF THE INVENTION

In view of the defects and improvement requirements of the prior art, the present invention provides a loose-wire winding motor, which aims to effectively suppress the AC copper loss in the loose-wire winding motor.

In order to achieve the above purpose, the present invention provides a loose-wire winding motor, which includes a stator, a rotor magnetic steel and a rotor iron core from the outside to the inside in the radial direction. The stator coils are placed in the stator slots formed between the stator teeth. It is formed by winding M parallel conductors, M is a positive integer, and two end covers are respectively provided at both ends of the stator in the axial direction;

When two stator coils are connected in series, transposition is performed according to the inductance of the parallel conductors, so that the inductance difference between the M series conductors obtained in series is minimized;

Among them, a series conductor is formed by connecting two parallel winding conductors taken from two stator coils in series.

The inductance of the series conductors is the sum of the inductances of the two parallel-wound conductors; in the present invention, the stators are transposed based on the parallel-wound conductors when they are connected in series, so that the inductance difference between the series conductors formed in series is minimized. The transposition method will make the parallel conductor with larger inductance in one coil connect in series with the parallel conductor with smaller inductance in the other coil, and finally balance the inductance of each series conductor as much as possible, thereby effectively reducing circulating current and suppressing AC copper loss.

Further, at the end where the outgoing terminal of the stator coil is located, a wiring board is also fixed, and the wiring board is located between the stator and the end cover and is in close contact with the end of the stator coil;

The wiring board includes a fixing ring and a plurality of junction boxes arranged on the outer surface of the fixing ring in the circumferential direction.

In the present invention, a terminal board closely connected with the stator coil end is arranged at one end of the stator, and the terminal board can serve as a good heat dissipation medium for the stator coil end while facilitating the series connection of the coils, thereby increasing the heat dissipation contact area.

Further, the wiring copper bars in the wiring slot are placed in a stepped shape along the axial direction, thereby providing a larger moving space for the welding components.

Further, when the parallel winding conductors are connected in series, the parallel winding conductors in series are pressed on the corresponding wiring copper bars by voltage welding; compared with spot welding, the present invention uses voltage welding to press the parallel winding conductors to the corresponding wiring. On the copper bar, the welding point between the parallel conductor and the copper bar is made stronger and firmer, thereby improving the safety and reliability of the motor.

Further, heat dissipation ribs are provided on the peripheral outer surface of the junction box, thereby enhancing the heat dissipation effect of the junction board.

Further, the wiring board is made by 3D printing, thereby making the overall structure compact, safe and reliable.

Further, between the wiring board and the end cover, a pressing ring is also included; the pressing ring is used for pressing the wiring board to avoid radial movement thereof.

Further, the M parallel-wound conductors in the stator coil are arranged in an arrangement that minimizes the layering of the parallel-wound conductors in the stator coil along the slot depth direction; using this arrangement, the parallel windings in the final coil are unloaded. The conductors will form a cluster-like arrangement, which can effectively reduce the difference in the interlinkage flux between each parallel conductor and effectively reduce the AC copper loss.

Further, slot wedges inserted into the stator slots in the axial direction are arranged at the slots of the stator, and the radial height of the slot wedges is greater than a preset threshold value.

In the present invention, by setting a larger (radial height greater than a preset threshold) slot wedge at the stator slot, the entire coil can be further squeezed by the slot wedge to the bottom of the stator slot, so as to be far away from the high flux leakage area of the slot, and the stator The parallel conductors of the slot are arranged along the circumference of the arc, so as to further reduce the difference in the flux linkage between the parallel conductors, reduce the circulation loss between the parallel conductors, and reduce the AC copper loss; at the same time, due to the stator coil and the slot The wedge is in close contact, which can increase the heat dissipation area of the stator coil and enhance the heat dissipation effect on the stator coil.

Further, the slot wedge is an arched slot wedge.

Since the magnetic flux leakage is mainly distributed in the slot and the magnetic field lines of the slot usually present an arched distribution, the present invention installs an arcuate slot wedge at the slot at the bottom of the stator slot, which can effectively reduce the magnetic flux leakage between the parallel conductors caused by the slot flux leakage. Circulating current loss, further reducing AC copper consumption.

In general, through the above technical solutions conceived by the present invention, the following beneficial effects can be achieved:

(1) In the present invention, when the stators are connected in series, each parallel conductor is transposed, so that the inductance difference between the series conductors formed in series is minimized, which can effectively reduce the circulating current and suppress the AC copper loss.

(2) In the present invention, a terminal board closely connected with the end of the stator coil is provided at one end of the stator. While facilitating the series connection of the coils, the terminal board can serve as a good heat dissipation medium for the end of the stator coil and increase the heat dissipation contact area.

(3) In the scattered-wire winding motor provided by the present invention, the M parallel-wound conductors in the stator coil are arranged in an arrangement that minimizes the layers of the parallel-wound conductors in the stator coil along the slot depth direction, which can effectively reduce the number of parallel wound conductors in the stator coil. The difference in the interlinkage flux of the root and wound conductors effectively reduces the AC copper loss.

(4) In the present invention, a larger slot wedge is arranged at the slot of the stator, so that the entire coil can be pressed towards the bottom of the stator slot by the slot wedge, so as to be far away from the high leakage area of the slot, and the parallel conductors of the stator slot are along the The arcs are arranged in the circumferential direction, thereby further reducing the difference in the flux linkage between the parallel conductors, reducing the circulating current loss between the parallel conductors, and reducing the AC copper loss; at the same time, due to the close contact between the stator coil and the slot wedge, the stator can be enlarged. The heat dissipation area of the coil enhances the heat dissipation effect on the stator coil.

(5) In the preferred solution of the loose-wire winding motor provided by the present invention, the slot wedge is an arched slot wedge, which can effectively reduce the circulating current loss between the parallel conductors caused by the leakage flux of the slot, and further reduce the AC copper consumption.

Description of drawings

FIG. 1 is a three-dimensional exploded view of the structure of a loose-wire winding motor provided by an embodiment of the present invention;

2 is a schematic structural diagram of a wiring board provided by an embodiment of the present invention;

3 is a cross-sectional view of a junction box provided by an embodiment of the present invention;

4 is a schematic diagram of a welding method provided by an embodiment of the present invention;

FIG. 5 is a structural diagram of a wiring board installation and fixing provided by an embodiment of the present invention;

6 is a cross-sectional view of a wiring board installation and fixing provided by an embodiment of the present invention;

FIG. 7 is a schematic diagram of the arrangement of parallel conductors according to an embodiment of the present invention;

8 is a front view of a stator coil provided by an embodiment of the present invention;

9 is a schematic diagram of a slot wedge provided by an embodiment of the present invention;

Throughout the drawings, the same reference numbers are used to refer to the same elements or structures, wherein:

1 is the stator, 11 is the stator core, 12 is the stator coil, 14 is the slot wedge, 2 is the rotor magnet, 3 is the rotor core, 4 is the casing, 5 is the front end cover, 6 is the rear end cover, 7 is the bearing, 8 is a wiring board, 81 is a fixing ring, 82 is a junction box, 83 is a wiring copper bar, 84 is a heat dissipation rib, and 9 is a pressure ring.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

In the present invention, the terms "first", "second" and the like (if present) in the present invention and the accompanying drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

Before explaining the technical solution of the present invention in detail, take a commonly used 12-slot, 10-pole, six-phase surface-mounted loose-wire winding motor as an example, and briefly describe the basic structure of the traditional loose-wire winding motor as follows:

As shown in Figure 1, the scattered-wire winding motor includes a stator 1, a rotor magnetic steel 2 and a rotor iron core 3 in turn from the outside to the inside in the radial direction. The rotor magnetic steel 2 is uniformly attached to the surface of the rotor iron core 3 in the circumferential direction; The stator teeth are arranged along the circumferential direction, and stator slots are formed between adjacent stator teeth. The stator coils 12 are placed in the stator slots formed between the stator teeth. Each stator coil is composed of one or more coils. Here, the number of parallel conductors in the stator coil is denoted as M, and M is a positive integer; a casing 4 is also provided outside the stator 1, and two end caps are respectively provided at both ends of the stator 1 in the axial direction. , that is, the front end cover 5 and the rear end cover 6, and a bearing 7 is also provided on the end cover. In the stator slot of the traditional scattered-wire winding motor, the parallel conductors forming the stator coil are arranged in a disorderly manner, and the position of the parallel conductor is uncertain, and there is a risk of excessive copper consumption.

The following are examples:

A loose-wire winding motor, as shown in Figure 1, when two stator coils are connected in series, transposition is performed according to the inductance of the parallel-wound conductors, so that the inductance difference between the M series conductors obtained in series is minimized;

Among them, a series conductor is formed by two parallel winding conductors taken from two stator coils in series;

The inductance of the series conductors is the sum of the inductances of the two parallel-wound conductors; in the present invention, the stators are transposed based on the parallel-wound conductors when they are connected in series, so that the inductance difference between the series conductors formed in series is minimized. The transposition method will make the parallel conductor with larger inductance in one coil connect in series with the parallel conductor with smaller inductance in the other coil, and finally balance the inductance of each series conductor as much as possible, thereby effectively reducing circulating current and suppressing AC copper loss;

For the convenience of description, the following takes two stator coils A and B wound by four parallel conductors as an example to explain the transposition method in this embodiment; the four parallel conductors in the stator coil A are shown in sequence. are A ₁ ～A ₄ , and the inductances of the parallel-wound conductors are arranged from large to small as A ₁ -A ₂ -A ₃ -A ₄ ; the four parallel-wound conductors in the stator coil B are sequentially represented as B ₁ ～B ₄ , And the inductances of the parallel conductors are arranged from large to small as B ₁ -B ₂ -B ₃ -B ₄ ; before transposition, the parallel conductors are connected as follows: A ₁ -B ₁ , A ₂ -B ₂ , A ₃ -B ₃ , A ₄ -B ₄ ; in order to minimize the inductance difference between the series conductors formed in series, the parallel conductors with larger inductance in stator coil A will be paralleled with the smaller inductance in stator coil B. The winding conductors are connected in series, and after transposition, the connection between the parallel winding conductors is: A ₁ -B ₄ , A ₂ -B ₃ , A ₃ -B ₂ , A ₄ -B ₁ .

In this embodiment, the six-phase outgoing terminal of the stator coil 12 is located at the end of the stator 1 close to the rear end cover 6. As shown in FIG. 1, FIG. 5 and FIG. 6, the end where the outgoing terminal of the stator coil 12 is located is also fixed. There is a wiring board 8, and the wiring board 8 is located between the stator 1 and the rear end cover 6 and is in close contact with the end of the stator coil 12;

The structure of the terminal board 8 is shown in FIG. 2, including a fixed ring 81 and a plurality of terminal boxes 82 arranged on the outer surface of the fixed ring in the circumferential direction. The number of the terminal boxes 82 is determined according to the number of stator coils that need to be connected in series. In this embodiment , the motor is also 12 slots and 10 poles, a total of 6 groups need to be connected in series, and the corresponding number of junction boxes 82 is 6; the junction box 82 is provided with a circumferentially open wiring slot, and the wiring slot is provided with a wiring copper bar 83; The plate 8 is closely connected with the end of the stator coil 12, while facilitating the series connection of the coils, the terminal plate 3 can act as a good heat dissipation medium for the end of the stator coil, increasing the heat dissipation contact area;

As a preferred embodiment, as shown in FIG. 3 , the wiring copper bars 83 in the wiring slot are placed in a stepped shape along the axial direction, and are placed in staggered order, thereby providing greater movement space for the welding components.

As a preferred embodiment, when the parallel winding conductors are connected in series, the parallel winding conductors in series are pressed on the corresponding wiring copper bars by voltage welding; The conductor to be welded after stripping the insulation is pressed on the wiring copper bar. Compared with spot welding, this welding method is stronger and firmer, has higher safety and reliability, and has a higher degree of automation.

As a preferred embodiment, as shown in FIG. 2 , FIG. 4 and FIG. 5 , heat dissipation ribs 84 are provided on the peripheral outer surface of the junction box 82 , thereby enhancing the heat dissipation effect of the junction board.

As an optional implementation manner, in this embodiment, the wiring board is made by 3D printing, thereby making the overall structure compact, safe and reliable.

As an optional embodiment, as shown in FIG. 1 , FIG. 5 and FIG. 6 , between the terminal block 8 and the rear end cover 6 , a pressure ring 9 is further included; the pressure ring is used to press the terminal block to avoid the radial movement occurs;

During installation, the terminal board 8 can be fixed on the stator 1 by using adhesives such as super glue. After the series connection of the stator coils is completed, the terminal board 8 is pressed by the pressing ring 9 so that it is not easy to move in the radial direction. , and then fix it on the rear end cover 6 as a whole, and use a long screw to fix the terminal board, the pressure ring and the rear end cover to make it a whole. The whole installation structure is compact and reliable, and there is no additional axial length. The space utilization rate of the mechanical structure is high; in other embodiments of the present invention, the outgoing terminal of the stator coil is located at the end of the stator 1 close to the front end cover 5, and the wiring board 2 is correspondingly located between the stator 1 and the front end cover 5 and is connected to the stator coil. The ends of 12 are in close contact, and the installation method is similar to that in this embodiment, which will not be repeated here.

As a preferred embodiment, in this embodiment, the M parallel-wound conductors in the stator coil 12 are arranged in a manner that minimizes the layers of the parallel-wound conductors in the stator coil along the slot depth direction;

With this arrangement, the parallel-wound conductors in the stator coil will eventually form a cluster-like arrangement structure; without loss of generality, in this embodiment, the number of parallel-wound conductors in the stator coil is 4, and its row The layout is shown in Figure 7; this embodiment adopts the lower limit of this layout, which can effectively reduce the difference in the interlinkage flux of each parallel-wound conductor and effectively reduce the AC copper loss.

As a preferred embodiment, as shown in FIG. 8 , in this embodiment, a slot wedge 14 inserted into the stator slot in the axial direction is further provided at the stator slot, and the radial height of the slot wedge 14 is greater than a preset threshold value ;

In this embodiment, a larger slot wedge is arranged at the slot of the stator. Specifically, the radial height of the slot wedge is greater than a preset threshold, so that the entire coil can be pressed toward the bottom of the stator slot by the slot wedge, so as to be far away from the slot height. In the magnetic leakage area, and the parallel conductors of the stator slots are arranged along the circumference of the arc, so as to further reduce the difference in the flux linkage between the parallel conductors, reduce the circulating current loss between the parallel conductors, and reduce the AC copper loss; , due to the close contact between the stator coil and the slot wedge, the heat dissipation area of the stator coil can be increased, and the heat dissipation effect of the stator coil can be enhanced; the threshold value of the radial height of the slot wedge can be set according to the actual motor size and the distribution of the magnetic flux leakage area of the slot. To ensure that the slot wedge is inserted enough to keep the coil away from the high leakage flux area of the slot.

As a preferred embodiment, as shown in FIG. 9 , in this embodiment, the slot wedge 14 is an arched slot wedge.

Since the magnetic flux leakage is mainly distributed in the slot and the magnetic field lines of the slot usually exhibit an arched distribution, in this embodiment, an arcuate slot wedge is added to the slot at the bottom of the stator slot, which can effectively reduce the gap between the parallel conductors caused by the magnetic flux leakage of the slot. The circulating current loss further reduces the AC copper loss.

In general, the loose-wire winding motor provided by the present invention adopts a special transposition method and off-line process, and optimizes the motor structure, has a good effect of suppressing AC copper loss, and does not change the corresponding motor. The electromagnetic environment makes full use of the internal space of the motor.

Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, etc., All should be included within the protection scope of the present invention.

Claims (10)

1. A motor with a scattered wire winding sequentially comprises a stator, rotor magnetic steel and a rotor iron core from outside to inside along the radial direction, wherein stator coils are placed in stator slots formed between stator teeth, each stator coil is formed by winding M parallel wound conductors, M is a positive integer, and two end covers are respectively arranged at two axial ends of the stator;

when two stator coils are connected in series, transposition is carried out according to the inductance of the parallel winding conductor, so that the difference of the inductance among M series conductors obtained by series connection is minimum;

wherein, a series conductor is formed by two parallel winding conductors respectively taken from two stator coils and connected in series.

2. The loose-wire winding motor of claim 1, wherein a terminal plate is further fixed to an end of the stator coil where the outlet terminal is located, the terminal plate being located between the stator and the end cover and being in close contact with the end of the stator coil;

the wiring board comprises a fixing ring and a plurality of wiring boxes arranged on the outer surface of the fixing ring along the circumferential direction, a wiring groove with an opening in the circumferential direction is formed in each wiring box, and a wiring copper bar is arranged in each wiring groove.

3. The random winding motor of claim 2, wherein the copper bar conductors in said conductor slots are arranged in a step-like manner in the axial direction.

4. The electrical machine with discrete wire windings as claimed in claim 2 wherein when the parallel wound conductors are connected in series, the parallel wound conductors connected in series are pressed onto the corresponding connecting copper bars by means of voltage welding.

5. The random winding motor of claim 2, wherein the junction box is provided with heat dissipating ribs on a circumferential outer surface thereof.

6. The random winding motor of claim 2, wherein the terminal plate is formed by 3D printing.

7. The random winding motor of claim 2, further comprising a compression ring between the terminal plate and the end cap; the clamping ring is used for pressing the wiring board to prevent the wiring board from moving radially.

8. The random-winding motor of any one of claims 1 to 7, wherein the M parallel-wound conductors in the stator coil are arranged in an arrangement that minimizes stratification of the parallel-wound conductors in the stator coil in a direction of a slot depth.

9. The random winding machine of any of claims 1-7, wherein the stator slot is provided with a slot wedge axially inserted into the stator slot, the radial height of the slot wedge being greater than a predetermined threshold.

10. The random winding machine of claim 9 wherein the slot wedges are arcuate shaped slot wedges.

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