CN105703569A - Fabrication method for amorphous alloy motor stator iron core - Google Patents

Abstract

The invention belongs to the technical field of motor manufacturing, and in particular relates to a method for preparing an amorphous alloy stator core, comprising the following steps: cutting an amorphous alloy strip into a plurality of amorphous alloy sheets; Diluted inorganic high-temperature glue is coated on the surface of the metal sheet, and multiple amorphous alloy sheets are laminated into a multi-layer laminate. There are multiple metal sheets at intervals of a certain thickness in the multi-layer laminate; paste on the outermost two ends of the multi-layer laminate. Multiple metal sheets form a composite laminate; clamp the composite laminate, solidify, process small round holes, wire cut, anneal heat treatment, and spray antirust agent. The final heat treatment of this method reduces the influence of mechanical stress on the magnetic properties of the amorphous alloy during the processing of the stator core; the manufactured stator core has high mechanical strength, and positioning grooves are cut on the outer circle of the stator, and non-magnetic cylindrical pins are used to connect with the motor. The base or cooling water jacket is fixed to avoid the influence of traditional fixing methods or interference fit fixing mechanical stress on the magnetic properties of the stator core.

Description

Preparation method of amorphous alloy motor stator core

technical field

The invention belongs to the technical field of motor manufacturing, in particular to a method for preparing an amorphous alloy stator core.

Background technique

Amorphous alloy materials have the advantages of high magnetic permeability and low AC core loss (core loss is one-tenth to one-fifth of traditional silicon steel sheets), and are used in power frequency transformers, power frequency reactors, and high frequency reactors. Applications in the field of inverters and transformers, high-speed motors or multi-pole pairs of high-frequency motors have received more and more attention. For example, the number of poles of the precision high-speed grinding machine is 4, the speed is 36000r/min, and the alternating frequency of the fundamental magnetic field in the stator core is 1200Hz; the electric vehicle drive motor has 10 poles, and the frequency of the stator current is 12000r/min. 1000Hz. High-speed motors or high-frequency motors using amorphous alloy materials as stator cores can significantly reduce core loss and improve motor efficiency compared to silicon steel sheets as stator cores. However, amorphous alloy materials are sensitive to mechanical stress, and excessive mechanical stress during processing or assembly will greatly reduce the magnetic permeability of amorphous alloy materials.

The stator core of the traditional silicon steel sheet motor is usually stamped with two or more gaps on the outer circle of the stator punching sheet, and passes through the outer circular gap when a certain pressure is applied to the multi-layer stator punching sheet in the axial direction for lamination. The method of electric welding fixes the multi-layer laminations into a complete stator core.

There is also a stator core forming method that evenly distributes and punches a plurality of dovetail slots on the outer circle of the silicon steel sheet punching, and laminates the multi-layer stator punching sheets to form a stator core, and axially penetrates the elastic narrow steel plate into the dovetail slots. At the end of the stator iron core, the elastic narrow steel plate is bent into a compression buckle, so that the multi-layer stator punches are compressed into a complete stator iron core.

Or for a motor with a slightly larger stator outer diameter, 6 or more rectangular slots are evenly distributed on the outer circle of the stator punch, and the multi-layer stator punch is stacked to form a stator core, and the two ends of the stator core are close to the outer circle Place a steel annular pressure ring at the place, put a narrow steel plate in the axial rectangular slot of the stator core, bend the narrow steel plate outside the annular pressure ring at both ends and overlap the pressure ring, When a certain axial pressure is applied to the shaped pressure ring and the stator core, the narrow steel plate and the end annular pressure ring are welded together by electric welding, so that the stator core becomes a whole and meets a certain lamination coefficient requirement. .

There are certain defects in these three ways of compressing the stator punching sheet, whether it is electric welding welding line, stator pressing buckle, or narrow steel plate in the axial rectangular slot, it is difficult for the leakage magnetic field of the outer circle of the stator core. It is equivalent to the squirrel cage guide bar, which will generate the electromotive force of the same frequency as the stator winding, and directly short the stator punch or the steel annular pressure ring at both ends of the stator, forming an additional current between the stator punch and increasing The eddy current loss of the stator core. In order to avoid the contact between the stator buckle and the stator core and increase the additional eddy current loss, there is a method of pressing the steel buckle to cover the insulating sleeve so that the buckle does not directly contact the stator core.

For the development stage of silicon steel sheet motors or prototypes with high performance requirements, first brush the two sides of each silicon steel sheet twice with acetal resin diluted with absolute ethanol, and after drying, pressurize the multiple silicon steel sheets with a clamp. Keep it at a certain temperature for a certain period of time for curing, and then wire cut to become a complete stator core. However, acetal resin is an organic resin with a maximum temperature of 155 degrees Celsius, which is not suitable for heat treatment of amorphous alloys at 350 degrees Celsius and above.

The traditional method of assembling the stator core of the silicon steel sheet with the motor base and the cooling water jacket is to radially install one or more screw jackscrews on the base or the cooling water jacket to directly apply a radial force to the outer circle of the stator core to prevent The stator core moves axially and radially in series.

The 1986 patent W099/66624 of Honeywell Corporation of the United States announced an amorphous alloy stator with high-efficiency radial magnetic flux. toothed stator. The stator structure formed by this method contains a large number of air bubbles between discrete amorphous sheets, which increases the reluctance of the magnetic circuit, partially offsets the advantages of high magnetic permeability of amorphous alloy materials, and requires more excitation when the motor is running. Magnetomotive force or excitation current.

German patents DE2805435 and DE2805438 disclose a method for preparing an amorphous iron core stator, which is to divide the stator into a winding piece and a pole piece, and a non-magnetic material is inserted into the connection between the winding piece and the pole piece, and the winding piece The laminations are connected to each other by welding. This connection method increases the effective gap and correspondingly increases the reluctance of the magnetic circuit. Additionally, this method of joining amorphous metal laminations using welds will recrystallize the amorphous metal at and near the junction, thereby increasing reluctance and iron losses in the stator.

Invention patent CN201010211940.7 uses conventional amorphous alloy powder as raw material, fully mixes amorphous alloy powder and adhesive, and then puts the amorphous alloy powder mixed with adhesive in a mold to form an amorphous alloy stator iron core. The method for preparing the amorphous alloy stator core has high material utilization rate and less waste. However, it is difficult to manufacture a stator core with a complex stator groove. The outer circle of the amorphous alloy stator core is smooth, and the invention patent CN201010211940.7 does not provide a method for fixing it to the motor frame or the cooling water jacket.

Patent CN2008100007282.2 discloses a method for preparing an amorphous alloy stator core for high-speed motors. The amorphous alloy strip is cut and laminated to form a laminated rod of amorphous alloy sheets with a predetermined thickness, and the laminated rod is annealed, The binder is impregnated, cured and then cut to form stator cores of desired shape and size. This method cuts the stator core after the heat treatment is completed, which will introduce new mechanical stress and reduce the magnetic permeability of the amorphous alloy material. The outer circle of the stator iron core prepared by this patent is smooth, and there is no fixing method between the stator iron core and the motor frame or the cooling water jacket.

Contents of the invention

In order to overcome the deficiencies in the prior art, the invention provides a method for preparing an amorphous alloy strip stator core.

The specific technical solutions are:

The preparation method of the amorphous alloy stator core comprises the following processes:

(1) cutting the amorphous alloy strip into multiple amorphous alloy sheets of predetermined size;

(2) Simultaneously cut multiple pieces of metal sheets of the same size. The material of the metal sheets is one of the following: high-frequency silicon steel sheet, high-strength aluminum alloy sheet or magnesium alloy sheet. A round hole is opened in the center of the metal sheet and deburred. ;

(3) The surface of the amorphous alloy sheet and the metal sheet is coated with diluted inorganic high-temperature glue, and the thickness of the glue is less than 1 micron;

(4) Laminate a plurality of amorphous alloy sheets into a multi-layer laminate, and a plurality of metal sheets are sandwiched at a certain interval in the multi-layer laminate; paste multiple metal sheets on the outermost two ends of the multi-layer laminate to form a composite laminate Sheet, no glue on the outer surface of the outermost metal sheet;

(5) Clamp the composite laminate with a pair of aluminum alloy plates or epoxy resin glass laminates, apply pressure, and cure in a high-temperature oven;

(6) For the solidified composite lamination, the small round hole is axially processed by the electric spark method from the position of the outermost metal sheet round hole. The diameter of the small round hole is smaller than or equal to the round hole of the metal sheet, and the small round hole axially runs through the entire Composite lamination;

(7) Cut the composite lamination into a stator core according to the design size of the stator core by wire cutting method, that is, cut out the inner circle of the stator, the slots of the stator, the outer circle of the stator and the semicircular positioning groove on the outer circle;

(8) Carry out annealing heat treatment to the stator core after cutting, apply a magnetic field in the circumferential direction of the stator core during annealing heat treatment, or apply a magnetic field in the same direction as the magnetic field line when the motor is actually running;

(9) Spray anti-rust agent on the heat-treated and cooled stator core.

Compared with the prior art, the preparation method of the amorphous alloy stator core provided by the present invention has the following characteristics:

Because the amorphous alloy material is very hard and brittle, it is not suitable for conventional machining methods such as stamping, cutting, drilling, etc., and EDM is used.

The magnetic permeability of amorphous alloy materials is very sensitive to mechanical stress. High-frequency silicon steel sheets, high-strength aluminum alloy sheets or magnesium alloy sheets are added to the two ends and the middle of the amorphous alloy stator core, which increases the mechanical strength of the amorphous alloy stator tooth top and the end teeth of the iron core, and reduces the stator iron. The mechanical stress caused by the slot wedge and winding end shaping during the core insertion process has an adverse effect on the magnetic properties of the amorphous alloy stator.

The amorphous alloy sheet is bonded with high-temperature inorganic glue, so that the stator core can withstand high temperature during heat treatment after processing.

Heat treatment is performed after the entire stator core is processed. If heat treatment is performed in advance, subsequent processing will bring new mechanical stress;

Cut a positioning slot on the outer circle of the stator, and fix it with the motor cooling water jacket or the stator frame with epoxy glass fiber, or polytetrafluoroethylene or modified nylon PA66 and other non-magnetic cylindrical pins, so that the stator core and the frame or The cooling water jacket is in multi-point contact, which not only transmits the torque in the circumferential direction, so that the stator core will not move in the circumferential direction, but also avoids the influence of the local force of the traditional fixing method on the magnetic permeability of the stator core.

Description of drawings

Fig. 1 is a schematic diagram of the lamination process of the amorphous alloy stator core of the embodiment.

Fig. 2 is a cross-sectional view of an amorphous alloy stator core of an embodiment.

Fig. 3 is a left view of the amorphous alloy stator core with high-frequency silicon steel sheets added at both ends and in the middle of the embodiment.

Fig. 4 is a schematic diagram of a thin-walled copper cylinder to which a magnetic field in a circumferential direction is applied during heat treatment of an amorphous alloy stator core in an embodiment.

Fig. 5 is a left view of an amorphous alloy stator core with high-frequency silicon steel sheets at both ends and an aluminum alloy sheet added in the middle of the embodiment.

Fig. 6 is a cross-sectional view of the inner stator for applying a rotating magnetic field during heat treatment of the amorphous alloy stator core of the embodiment.

detailed description

Below in conjunction with accompanying drawing and preferred embodiment the present invention is described as follows:

Example 1

According to the method of the present invention, the specific steps of the amorphous alloy stator core preparation method are as follows:

1) Cut the amorphous alloy Fe _83.5 B ₁₅ Cu _1.5 strip into multiple amorphous alloy sheets with a length of 250 mm and a width of 140 mm after shearing.

2) Cut 15 high-frequency silicon steel sheets with a length of 250 mm, a width of 140 mm, and a thickness of 0.2 mm at the same time, and drill two round holes with a diameter of 20 mm at a distance of 125 mm from the center line of the high-frequency silicon steel sheet, and Deburring.

3) Brush the amorphous alloy sheet and high-frequency silicon steel sheet with silicate inorganic high-temperature glue with a temperature resistance of 500 degrees Celsius, and adjust the concentration of the high-temperature glue by adding absolute alcohol with a concentration greater than 96% in the high-temperature glue to ensure non-toxic The thickness of each side of the crystal alloy sheet and high-frequency silicon steel sheet coated with glue is less than 1 micron. Among them, two high-frequency silicon steel sheets are only coated with high-temperature glue on one side. Before applying high-temperature glue, it is necessary to preheat the amorphous alloy sheet and high-frequency silicon steel sheet to 60 degrees Celsius.

4) Laminate multiple amorphous alloy sheets coated with high-temperature glue to form a multi-layer laminated rod 1. When laminating the amorphous alloy, place five high-frequency silicon steel sheets 5 at both ends of the multi-layer laminated rod 1, two of which The non-adhesive side of the single-side glue-coated high-frequency silicon steel sheet faces the outer end of the iron core.

5) When laminating amorphous alloy sheets, five high-frequency silicon steel sheets 6 coated with high-temperature glue on both sides are placed in the middle of the amorphous alloy multilayer rod 1 at a position passing 32 mm in axial length.

6) Clamp the multi-layer amorphous alloy laminate with high-frequency silicon steel sheets with two aluminum alloy pressure plates 2 with a thickness of 20 mm, and apply a pressure of 80 MPa by evenly tightening six nuts 3 and bolts 4 . The upper aluminum alloy plate 2 and the lower aluminum alloy splint 7 used to clamp the amorphous alloy multilayer laminate require that the two clamping surfaces be flat, smooth and parallel to each other. Put the multi-layer amorphous alloy lamination in a high-temperature oven, control the temperature at 180-220 degrees Celsius to solidify for 15 minutes, and then cool with the furnace.

A schematic diagram of the process of laminating multi-layer amorphous alloy laminations is shown in Fig. 1 .

7) A circular hole with a diameter of 16 mm is machined axially from the position of the round hole of the high-frequency silicon steel sheet on the end face of the solidified amorphous alloy multi-layer rod, and the round hole axially runs through the entire amorphous alloy multi-layer rod. In order to pass through the molybdenum wire for wire cutting when wire cutting the inner circle and tooth groove of the stator core, the axis of the axial center hole coincides with the axis of the stator core as much as possible.

8) Cutting the solidified amorphous alloy multi-layer laminated rod into two stator core blanks, the length, width and height of the blanks are respectively: 140mm, 125mm and 67mm. Then cut out the inner circle of the stator and the stator tooth groove, the outer circle of the stator and the semicircular positioning groove 9 used for positioning with the motor support or the cooling water jacket on the outer circle according to the design requirements of the stator core. The inner diameter of the stator is 60.2mm, the outer diameter is 115mm, and the stator has 24 slots evenly distributed. Among them, the radius of the semicircular positioning groove on the outer circle of the stator is 1.6mm, and the processing method is as follows: cut out three radiuses along the axial direction of the stator iron core at a position evenly distributed on the outer circle of the stator iron core and facing the bottom of the stator iron core. 1.6mm semicircular positioning groove 9, the axis of the semicircular positioning groove 9 is parallel to the axis of the inner circle of the stator core, and the notch faces outward along the radial direction of the stator. The semicircular positioning grooves 9 on the outer circle of the stator, the semicircular positioning grooves on the motor base or the cooling water jacket and the epoxy glass fiber cylindrical pins are used to fix the amorphous alloy stator core in the circumferential direction. The sectional view of the amorphous alloy stator core after cutting is shown in Figure 2, and the left view is shown in Figure 3.

9) Annealing heat treatment is performed on the cut amorphous alloy stator core to remove mechanical stress, and the annealing heat treatment is performed in a bell furnace filled with nitrogen. The annealing temperature is 390 degrees Celsius for 15 minutes, and then cooled with the furnace. During the annealing heat treatment, a magnetic field of a certain intensity is applied in the circumferential direction of the stator iron core. The specific method is to place a red copper cylinder 10 with a thin wall thickness of 1mm as shown in Figure 4 in the inner circle of the stator iron core 8, and the red copper cylinder 10 is connected with the stator core 8. There is an air gap of 0.3mm between the iron cores 8, and a direct current of 3-5A is passed through the terminal 11 until the furnace temperature cools down to room temperature.

9) Spray thin epoxy resin on the heat-treated and cooled amorphous alloy stator core for anti-rust treatment.

At this point, the preparation of the amorphous alloy stator core with high-frequency silicon steel sheets added at both ends and in the middle is completed.

Example 2

According to the method of the present invention, the specific steps of the amorphous alloy stator core preparation method are as follows:

1) Cut the amorphous alloy Fe ₈₅ B ₁₁ Si _4.0 strip into multiple amorphous alloy sheets with a length of 250 mm and a width of 140 mm after shearing.

2) Simultaneously cut 10 high-frequency silicon steel sheets with a length of 250 mm, a width of 140 mm, and a thickness of 0.2 mm. Then cut 10 pieces of high-strength aluminum alloy 7075-T651 sheets with a width of 250mm, a width of 140mm, and a thickness of 0.2mm, and drill two holes with a diameter of 20mm at a place where the center line of the high-frequency silicon steel sheet and the aluminum alloy sheet is 125mm apart. round hole, and deburring.

3) Brush the amorphous alloy sheet and high-frequency silicon steel sheet with silicate inorganic high-temperature glue with a temperature resistance of 500 degrees Celsius, and adjust the concentration of the high-temperature glue by adding absolute alcohol with a concentration greater than 96% in the high-temperature glue to ensure non-toxic Crystal alloy sheets, high-frequency silicon steel sheets, and high-strength aluminum alloy sheets are coated with glue less than 1 micron thick on each side. Among them, two high-frequency silicon steel sheets are only coated with high-temperature glue on one side. Before applying high-temperature glue, preheat the amorphous alloy sheet and high-frequency silicon steel sheet to 60 degrees Celsius.

4) Laminate multiple amorphous alloy sheets coated with high-temperature glue to form a multi-layer laminated rod. When laminating the amorphous alloy, place five high-frequency silicon steel sheets 5 at both ends of the multi-layer laminated rod, two of which are single-sided The non-glue-coated surface of the glue-coated high-frequency silicon steel sheet faces the outer end of the iron core.

5) When laminating amorphous alloy sheets, place five sheets of high-strength aluminum alloy 7075-T651 thin sheets 6 coated with high-temperature glue on both sides at every 21mm position in the axial length of the middle of the amorphous alloy multi-layer laminated rod.

6) Clamp the multi-layer amorphous alloy laminate with high-frequency silicon steel sheets and high-strength aluminum alloy sheets with two upper aluminum alloy plates 2 and lower aluminum alloy splints 7 with a thickness of 20mm, and fasten six Nut 3 and bolt 4 exert a pressure of 80MPa. Among them, the aluminum alloy plate 2 used to clamp the amorphous alloy multilayer laminate requires that the two clamping surfaces be flat, smooth and parallel to each other. Put the multi-layer amorphous alloy lamination in a high-temperature oven, control the temperature at 180-220 degrees Celsius to solidify for 15 minutes, and then cool with the furnace.

A schematic diagram of the process of laminating multi-layer amorphous alloy laminations is shown in Fig. 1 .

7) A circular hole with a diameter of 16 mm is machined axially from the position of the round hole of the high-frequency silicon steel sheet on the end face of the solidified amorphous alloy multi-layer rod, and the round hole axially runs through the entire amorphous alloy multi-layer rod. In order to pass through the molybdenum wire for wire cutting when wire cutting the inner circle and tooth groove of the stator core, the axis of the axial center hole coincides with the axis of the stator core as much as possible.

8) Cutting the solidified amorphous alloy multi-layer laminated rod into two stator core blanks, the length, width and height of the blanks are respectively: 140mm, 125mm and 67mm. Then cut out the inner circle of the stator and the stator tooth groove, the outer circle of the stator and the semicircular positioning groove 9 used for positioning with the motor support or the cooling water jacket on the outer circle according to the design requirements of the stator core. The inner diameter of the stator is 60.2mm, the outer diameter is 115mm, and the stator has 24 slots evenly distributed. Among them, the radius of the semicircular positioning groove on the outer circle of the stator is 1.6mm, and the processing method is as follows: cut out three radiuses along the axial direction of the stator iron core at a position evenly distributed on the outer circle of the stator iron core and facing the bottom of the stator iron core. 1.6mm semicircular positioning groove 9, the axis of the semicircular positioning groove 9 is parallel to the axis of the inner circle of the stator core, and the notch faces outward along the radial direction of the stator. The semicircular positioning grooves 9 on the outer circle of the stator, the semicircular positioning grooves 9 on the motor base or the cooling water jacket and the modified nylon PA66 cylindrical pins are used to fix the amorphous alloy stator core in the circumferential direction. The sectional view of the amorphous alloy stator core after cutting is shown in Figure 2, and the left view is shown in Figure 5.

9) Annealing heat treatment is performed on the cut amorphous alloy stator core to remove mechanical stress, and the annealing heat treatment is performed in a bell furnace filled with nitrogen. The annealing temperature is 380 degrees Celsius, the holding time is 75 minutes, and then cooled with the furnace. During the annealing heat treatment, a magnetic field of a certain strength is applied in the stator core in the same direction as the magnetic field line when the motor is actually running. The specific method is to place the inner stator as shown in Figure 6 in the inner circle of the stator core. The stator also has 24 slots. Air gap, the iron core of the inner stator is ordinary silicon steel sheet, the three-phase winding is designed to have the same number of pole pairs as the amorphous alloy iron core, the winding is copper wire insulated by ceramic tube, single-layer winding structure, and the number of conductors per slot is 4. Three-phase 50Hz 3-6A AC current is passed through the terminals to generate a rotating magnetic field. The induction intensity in the amorphous alloy stator core is about 0.1-0.2T until the furnace temperature cools down to room temperature.

9) Spray thin varnish on the heat-treated and cooled amorphous alloy stator core for anti-rust treatment.

A four-pole high-speed permanent magnet motor is designed by adding high-frequency silicon steel sheets at both ends and a stator core with high-strength aluminum alloy sheets in the middle. The two-dimensional magnetic density nephogram of the amorphous alloy part shows that a semicircle is cut and positioned on the outer circle of the stator. The magnetic density of the amorphous alloy near the groove increases, but it is still within the acceptable range. From the two-dimensional magnetic density cloud diagram of the aluminum alloy part, it can be seen that because the magnetic permeability of the aluminum alloy is very close to that of a vacuum, the magnetic density of the aluminum alloy part of the stator is very low, so the AC loss is very low.

So far, the preparation of the amorphous alloy stator core with high-frequency silicon steel sheets and high-strength aluminum alloy sheets is completed.

The above descriptions are only the best embodiments of the present invention, and are not intended to limit the implementation scope of the present invention. All equivalent changes and modifications made according to the patent scope of the present invention fall within the scope of the present invention.

Claims (1)

1. the preparation method of amorphous alloy stator iron core is characterized in that, comprises following process: (1) cutting the amorphous alloy strip into multiple amorphous alloy sheets of predetermined size; (2) Simultaneously cut multiple pieces of metal sheets of the same size. The material of the metal sheets is one of the following: high-frequency silicon steel sheet, high-strength aluminum alloy sheet or magnesium alloy sheet. A round hole is opened in the center of the metal sheet and deburred. ; (3) The surface of the amorphous alloy sheet and the metal sheet is coated with diluted inorganic high-temperature glue, and the thickness of the glue is less than 1 micron; (4) Laminate a plurality of amorphous alloy sheets into a multi-layer laminate, and a plurality of metal sheets are sandwiched at a certain interval in the multi-layer laminate; paste multiple metal sheets on the outermost two ends of the multi-layer laminate to form a composite laminate Sheet, no glue on the outer surface of the outermost metal sheet; (5) Clamp the composite laminate with a pair of aluminum alloy plates or epoxy resin glass laminates, apply pressure, and cure in a high-temperature oven; (6) For the solidified composite lamination, the small round hole is axially processed by the electric spark method from the position of the outermost metal sheet round hole. The diameter of the small round hole is smaller than or equal to the round hole of the metal sheet, and the small round hole axially runs through the entire Composite lamination; (7) Cut the composite lamination into a stator core according to the design size of the stator core by wire cutting method, that is, cut out the inner circle of the stator, the slots of the stator, the outer circle of the stator and the semicircular positioning groove on the outer circle; (8) Carry out annealing heat treatment to the stator core after cutting, apply a magnetic field in the circumferential direction of the stator core during annealing heat treatment, or apply a magnetic field in the same direction as the magnetic field line when the motor is actually running; (9) Spray anti-rust agent on the heat-treated and cooled stator core.