CN111245114B - Motor iron core based on metal 3D printing technology and manufacturing method thereof - Google Patents

Motor iron core based on metal 3D printing technology and manufacturing method thereof Download PDF

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Publication number
CN111245114B
CN111245114B CN202010062461.7A CN202010062461A CN111245114B CN 111245114 B CN111245114 B CN 111245114B CN 202010062461 A CN202010062461 A CN 202010062461A CN 111245114 B CN111245114 B CN 111245114B
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core
shell
rotor
soft magnetic
stator
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CN111245114A (en
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赵文娟
邱鑫
葛浩锐
杨建飞
施建平
杨继全
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Nanjing Normal University
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/12—Stationary parts of the magnetic circuit
    • H02K1/14—Stator cores with salient poles
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/22—Rotating parts of the magnetic circuit
    • H02K1/27—Rotor cores with permanent magnets
    • H02K1/2706—Inner rotors
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
    • H02K15/02—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
    • H02K15/02—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies
    • H02K15/03—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies having permanent magnets

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacture Of Motors, Generators (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)

Abstract

The invention discloses a motor iron core based on a metal 3D printing technology and a manufacturing method thereof, wherein the motor iron core comprises a stator iron core and a rotor iron core which are matched with each other, the stator iron core comprises a stator iron core outer shell and a stator iron core inner shell, and a plurality of stator slots which protrude outwards are uniformly formed on the stator iron core inner shell along the circumference; a stator core slot for containing the oxidized soft magnetic powder is enclosed between the stator core outer shell and the stator core inner shell; the rotor core comprises a rotor core outer shell and a rotor core inner shell, and a plurality of uniformly distributed linear inner grooves are formed in the inner periphery of the rotor core outer shell; and the parts except the linear inner groove between the rotor core outer shell and the rotor core inner shell are provided with different specifications of oxidized soft magnetic powder. According to the invention, different slots in the iron core are filled with different specifications of oxidized soft magnetic powder, and the eddy current loss of the motor is reduced by adjusting the particle size of the powder; the magnetic conductivity of the motor core can be adjusted and the magnetic circuit of the motor can be optimized by adjusting the looseness of the powder in the core slot, so that the performance of the motor is improved.

Description

Motor iron core based on metal 3D printing technology and manufacturing method thereof
Technical Field
The invention relates to a motor iron core, in particular to a motor iron core based on a metal 3D printing technology and a manufacturing method thereof.
Background
The traditional manufacturing method of the motor iron core mainly comprises a single-piece punching method and a splicing method. Both methods need to punch silicon steel sheets first, then laminate and splice, and finally complete welding, and the process is complex, the manufacture of the iron core with a complex shape is difficult, the universality of the die is not high, a large number of dies are needed, and the price is high.
In recent years, metal three-dimensional printing technology is rapidly developed, the three-dimensional printing technology which adopts a high energy source such as selective laser melting, sintering, electron beam melting and the like is the most mature, the rapid manufacturing of refractory and difficult-to-process metal materials can be realized, the method has wide application prospects in the fields of die manufacturing, aerospace, vehicles, medicine and the like, and a new idea is provided for manufacturing motor iron cores. After the metal three-dimensional printing technology is adopted, because the motor iron core is printed into a whole, the eddy current loss of the motor is increased along with the printing, and how to reduce the eddy current loss of the motor becomes a difficult point.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to provide a motor iron core with low eddy current loss based on a metal 3D printing technology; a second object of the present invention is to provide a method for manufacturing a motor core based on a metal 3D printing technique, which can reduce eddy current loss.
The technical scheme is as follows: the invention discloses a motor iron core based on a metal 3D printing technology, which comprises a stator iron core and a rotor iron core which are matched with each other, and is characterized in that: the stator core comprises a stator core shell, the stator core shell consists of a stator core outer shell and a stator core inner shell, and the stator core inner shell uniformly forms a plurality of stator slots which protrude outwards and are used for placing windings along the circumference; a stator core slot for containing the oxidized soft magnetic powder is enclosed between the stator core outer shell and the stator core inner shell;
the rotor core comprises a rotor core shell, the rotor core shell consists of a rotor core outer shell and a rotor core inner shell, the rotor core inner shell is arranged in the rotor core outer shell, and a plurality of uniformly distributed linear inner grooves for placing permanent magnets are formed along the inner periphery of the rotor core outer shell; the parts outside the straight-line-shaped inner groove between the rotor core outer shell and the rotor core inner shell are filled with different specifications of oxidized soft magnetic powder.
Two side surfaces of the straight-shaped inner groove extend to the inner wall of the rotor core shell to form a first inner groove; two long edges of two adjacent linear inner grooves, which are close to one side of the rotor core inner shell, are connected, and a second inner groove is formed by the two long edges, the inner wall of the rotor core outer shell and two side surfaces of the two adjacent linear inner grooves in a surrounding mode; the space enclosed by the rotor core inner shell, the linear inner groove and the second inner groove is a third inner groove, and different specifications of oxidized soft magnetic powder can be filled in different grooves.
The stator core slot, the first inner slot, the second inner slot and the third inner slot are respectively filled with soft magnetic oxide powder with different specifications, and the loose degrees of the soft magnetic oxide powder filled in the stator core slot, the first inner slot, the second inner slot and the third inner slot are different; the eddy current loss of the motor is reduced by adjusting the size of the oxidized soft magnetic powder particles, and the magnetic conductivity of the motor core can be adjusted by adjusting the porosity of the oxidized soft magnetic powder in different grooves.
The thickness of the stator iron core shell and the rotor iron core shell is adjustable, the heat conduction performance is good, and the heat dissipation area is large.
The oxidized soft magnetic powder is iron oxide powder or iron oxide silicon alloy powder.
The top of the stator core shell is provided with a first powder containing hole, the top of the rotor core shell is provided with a plurality of powder containing holes corresponding to the first inner groove, the second inner groove and the third inner groove, and the oxidized soft magnetic powder is filled into each groove through the powder containing holes.
The stator core shell and the rotor core shell are made by adopting a metal 3D printing technology, the production process is simple, the production period is short, and the utilization rate of materials is improved.
The invention relates to a manufacturing method of a motor iron core based on a 3D printing technology, which comprises the following steps:
(1) establishing a three-dimensional model of the motor iron core by a metal 3D printing technology, and reserving powder filling holes at positions needing to be filled with oxidized soft magnetic powder in the stator iron core shell and the rotor iron core shell;
(2) after printing is finished, pouring out the residual soft magnetic powder in the stator core shell and the rotor core shell;
(3) determining the optimal particle specification for reducing the eddy current loss by oxidizing the soft magnetic powder through experiments;
(4) determining the porosity of the oxidized soft magnetic powder at each part of the iron core through calculation;
(5) filling the iron core with oxidized soft magnetic powder;
(6) and closing the powder containing hole.
And (3) after filling different oxidized soft magnetic powder with different specifications in different powder filling holes, introducing rated current to the motor under the same experimental condition, and measuring the temperature rise of the rotor through a temperature sensor to find out the specification of the oxidized soft magnetic powder which enables the temperature rise of the rotor of the motor to be minimum.
In the step (4), the porosity calculation formula of the oxidized soft magnetic powder is specifically as follows:
Figure BDA0002374925740000021
in the formula, mnDenotes the mass of the oxidized powder in the nth powder vessel, VnThe volume of the nth powder groove is shown.
Has the advantages that: compared with the prior art, the invention has the beneficial effects that: (1) soft magnetic powder materials such as iron oxide powder with different porosities are filled in different grooves in the iron core, and the eddy current loss of the motor can be effectively reduced by adjusting the particle size of the powder; (2) the magnetic conductivity of the motor iron core can be adjusted and the magnetic circuit of the motor can be optimized by adjusting the looseness of powder at different parts of the iron core, so that the performance of the motor is improved; (3) the eddy current loss is basically concentrated on the iron core shell, but the thickness of the iron core shell can be adjusted, the heat conduction performance is good, and the heat dissipation area is large; (4) the iron core is printed by adopting a metal three-dimensional printing technology, the production process is simple, the production period is short, and the utilization rate of materials is improved.
Drawings
FIG. 1 is a schematic structural diagram of an electrical machine core according to the present invention;
FIG. 2 is a schematic structural diagram of a stator core of an electric machine according to the present invention;
FIG. 3 is a schematic structural diagram of a rotor core of an electric machine according to the present invention;
FIG. 4 is a radial cross-sectional view of a stator core of an electric machine in accordance with the present invention;
fig. 5 is a radial sectional view of a rotor core of an electric machine according to the present invention.
Detailed Description
The invention is described in further detail below with reference to specific embodiments and the attached drawing figures.
As shown in fig. 1 to 3, the present invention includes a stator core and a rotor core, both the stator core and the rotor core are of a hollow structure, the stator core is sleeved outside the rotor core, an air gap is provided between the stator core and the rotor core, as shown in fig. 3, the stator core includes a stator core housing 1 printed by a metal 3D printing technology, the stator core housing 1 includes a stator core outer housing 11 and a stator core inner housing 12, the stator core inner housing 12 is disposed inside the stator core outer housing 11 and concentrically disposed with the stator core outer housing 12, the stator core inner housing 12 uniformly forms a plurality of stator slots 13 along a circumference, and stator teeth are formed between two adjacent stator slots 13, in this embodiment, the number of the plurality of stator slots 13 is 12, and a winding is provided in the plurality of stator slots 13; a gap portion between the stator core outer shell 11 and the stator core inner shell 12 forms a stator core slot 14; as shown in fig. 1, a top shell is arranged at the top of a stator core shell 1, and a first powder containing hole 15 is formed in the top shell and positioned right above a stator core slot 14;
as shown in fig. 4, the rotor core includes a rotor core housing 2 printed by a metal 3D printing technology, the rotor core housing 2 includes a rotor core outer shell 21 and a rotor core inner shell 22, the rotor core inner shell 22 is disposed inside the rotor core outer shell 21 and concentrically disposed with the rotor core outer shell, and a plurality of linear inner grooves 23 are uniformly distributed along the inner circumference of the rotor core outer shell 21, in this embodiment, the number of the linear inner grooves 23 is 6, and the linear inner grooves are all used for placing permanent magnets; two side surfaces of the straight-shaped inner groove 23 extend to the inner wall of the rotor core housing 21 to form a first inner groove 24; two long sides of two adjacent linear inner grooves 23 close to one side of the rotor core inner shell 22 are connected, and form a second inner groove 25 together with the inner wall of the rotor core outer shell 21 and the short sides of the two adjacent linear inner grooves 23; the space enclosed by the rotor core inner shell 22, the straight inner groove 23, and the second inner groove 25 is a third inner groove 26. In this embodiment, the stator core housing 1 and the rotor core housing 2 have adjustable thicknesses, good thermal conductivity, and a large heat dissipation area, and the stator core housing 1 and the rotor core housing 2 are formed of core straps having a certain width. As shown in fig. 2, a top case is provided on the top of the rotor core housing 2, a second powder filling hole 27 is formed right above each first inner groove 24, a third powder filling hole 28 is formed right above each second inner groove 25, and a fourth powder filling hole 29 is formed right above each third inner groove 25.
Stator core slots 14, first inner slot 24, second inner slot 25, and third inner slot 26 are filled with oxidized soft magnetic powder of different specifications. In the embodiment, the oxidized soft magnetic powder is iron oxide powder or iron oxide silicon alloy powder, and the eddy current loss of the motor can be effectively reduced by adjusting the oxidation degree of the powder; the soft magnetic powder materials filled in the stator core slots 14, the first inner slot 24, the second inner slot 25 and the third inner slot 26 have different looseness, and the magnetic conductivity of the motor core can be adjusted and the magnetic circuit of the motor can be optimized by adjusting the looseness of the powder at different parts of the core, so that the performance of the motor is improved.
The invention relates to a manufacturing method of a motor iron core structure based on a 3D printing technology, which specifically comprises the following steps:
(1) establishing a three-dimensional model of the motor iron core by a metal 3D printing technology, and reserving powder filling holes at positions needing to be filled with oxidized soft magnetic powder in the stator iron core shell and the rotor iron core shell;
(2) after printing is finished, pouring out the residual soft magnetic powder in the stator core shell and the rotor core shell;
(3) determining the optimal particle specification for reducing the eddy current loss by oxidizing the soft magnetic powder through experiments;
(4) determining the porosity of the oxidized soft magnetic powder at each part of the iron core through calculation;
(5) filling the iron core with oxidized soft magnetic powder;
(6) and closing the powder containing hole.
In the step (3), after the oxidized soft magnetic powder with different specifications is filled in different powder filling holes, under the same experimental conditions, rated current is introduced into the motor, and the temperature rise of the rotor is measured by the temperature sensor, so that the oxidized soft magnetic powder with the minimum temperature rise of the rotor of the motor is found out.
In the step (4), the porosity calculation formula of the oxidized soft magnetic powder is specifically as follows:
Figure BDA0002374925740000041
mnthe n-th powder groove is filled with oxidized soft magnetic powderMass of powder, VnThe volume of the nth powder groove. In the present embodiment, the porosity of the oxidized soft magnetic powder in second inner groove 25 is greater than the porosity of the oxidized soft magnetic powder in first inner groove 24, and the porosity of the oxidized soft magnetic powder in first inner groove 24 is greater than the porosity of the oxidized soft magnetic powder in third inner groove 26.

Claims (9)

1. The utility model provides a motor core based on metal 3D printing technique, includes stator core and rotor core that mutually supports, its characterized in that: the stator core comprises a stator core shell (1), the stator core shell (1) is composed of a stator core outer shell (11) and a stator core inner shell (12), and a plurality of stator slots (13) which protrude outwards and are used for placing windings are uniformly formed in the stator core inner shell (12) along the circumference; a stator core slot (14) for containing oxidized soft magnetic powder is enclosed between the stator core outer shell (11) and the stator core inner shell (12);
the rotor iron core comprises a rotor iron core shell (2), the rotor iron core shell (2) is composed of a rotor iron core outer shell (21) and a rotor iron core inner shell (22), and a plurality of linear inner grooves (23) which are uniformly distributed and used for placing permanent magnets are arranged along the inner periphery of the rotor iron core outer shell (21); the parts except a linear inner groove (23) between the rotor core outer shell (21) and the rotor core inner shell (22) are filled with different specifications of oxidized soft magnetic powder;
two side surfaces of the linear inner groove (23) extend to the inner wall of the rotor core shell (21) to form a first inner groove (24); two long edges of one side of each two adjacent linear inner grooves (23) close to the inner shell (22) of the rotor core are connected, and a second inner groove (25) is formed by the two long edges and the inner wall of the outer shell (21) of the rotor core and two side faces of the two adjacent linear inner grooves (23) in a surrounding mode; the space enclosed by the rotor core inner shell (22), the linear inner groove (23) and the second inner groove (25) is a third inner groove (26).
2. The motor core based on metal 3D printing technology of claim 1, characterized in that: the stator core slots (14), the first inner slot (24), the second inner slot (25) and the third inner slot (26) are respectively filled with soft magnetic oxide powder with different specifications, and the soft magnetic oxide powder filled in the stator core slots (14), the first inner slot (24), the second inner slot (25) and the third inner slot (26) has different looseness.
3. The motor core based on metal 3D printing technology of claim 1, characterized in that: the thicknesses of the stator iron core shell (1) and the rotor iron core shell (2) are adjustable.
4. The motor core based on metal 3D printing technology of claim 1, characterized in that: the oxidized soft magnetic powder is iron oxide powder or iron oxide silicon alloy powder.
5. A motor core based on metal 3D printing technology according to claim 1, characterized in that: the top of the stator core shell (1) is provided with a first powder containing hole (15), and the top of the rotor core shell (2) is provided with a plurality of powder containing holes corresponding to the first inner groove (24), the second inner groove (25) and the third inner groove (26).
6. A motor core based on metal 3D printing technology according to claim 1, characterized in that: the stator core shell (1) and the rotor core shell (2) are manufactured by adopting a metal 3D printing technology.
7. A method for manufacturing a motor core based on metal 3D printing technology according to claim 1, characterized by comprising the steps of:
(1) establishing a three-dimensional model of the motor iron core by a metal 3D printing technology, and reserving powder filling holes at positions needing to be filled with oxidized soft magnetic powder in the stator iron core shell (1) and the rotor iron core shell (2);
(2) after printing is finished, pouring out the residual soft magnetic powder in the stator core shell (1) and the rotor core shell (2);
(3) determining the optimal particle specification for reducing the eddy current loss by oxidizing the soft magnetic powder through experiments;
(4) determining the porosity of the oxidized soft magnetic powder at each part of the iron core through calculation;
(5) filling the iron core with oxidized soft magnetic powder;
(6) and closing the powder containing hole.
8. The method for manufacturing a motor core based on a metal 3D printing technology according to claim 7, wherein: and (3) after filling different oxidized soft magnetic powder with different specifications in different powder filling holes, introducing rated current to the motor under the same experimental condition, and measuring the temperature rise of the rotor through a temperature sensor to find out the specification of the oxidized soft magnetic powder which enables the temperature rise of the rotor of the motor to be minimum.
9. The method for manufacturing a motor core based on a metal 3D printing technology according to claim 7, wherein: in the step (4), the porosity calculation formula of the oxidized soft magnetic powder is specifically as follows:
Figure FDA0003163682290000021
in the formula, mnDenotes the mass V of the oxidized soft magnetic powder contained in the nth powder tanknThe volume of the nth powder groove is shown.
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CN111564917A (en) * 2020-06-08 2020-08-21 南京师范大学 Motor rotor structure based on metal 3D printing technology
CN111769675B (en) * 2020-06-22 2021-06-08 南京师范大学 Motor based on liquid metal coil, manufacturing method and speed regulation method

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DE102013221965A1 (en) * 2013-10-29 2015-04-30 Volkswagen Aktiengesellschaft Process for producing a molded part and electric machine with such a molded part

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