Low eddy current loss stator end structure and electric machine

Abstract

The application discloses a low eddy current loss stator end structure, which comprises a stator tooth pressing plate, a yoke pressing plate and an end cooler. The stator tooth pressing plate is integrally staggered and pressed by a plurality of fan-shaped segments which are pressed by stamping sheets. The yoke pressing plate is made of non-magnetic material or has a stainless steel magnetic shielding layer outside a magnetic material. The end cooler is die-cast aluminum, is uniformly distributed along a circumference and is electrically connected between each segment. The application solves the winding end loss problem of high-load motors, guarantees the cooling effect, prevents the generation of local overheating points and improves the overall motor efficiency, and can be widely applied in the field of motors.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electric machines, and particularly relates to a low eddy current loss stator end structure and a low end eddy current loss electric machine. BACKGROUND

[0002] With the increasing requirement of electric machine torque density index, it is common to use higher electric load in electric machine design. However, too high load means that the end leakage magnetic field of the winding is enhanced, which will induce more eddy current loss in the end structure of the electric machine such as the tooth pressure plate and the yoke pressure plate. On the other hand, more heat will be generated at the winding end, and the traditional cooling type such as air cooling has the problems of high noise and insufficient cooling efficiency.

[0003] A common solution is to set a cooler made of metal material with good thermal conductivity around the winding end to achieve efficient cooling mainly by heat conduction. However, the metal material is also in the end leakage magnetic field region of the current, which will inevitably generate a large amount of eddy current loss.

[0004] In summary, without effective measures, the additional eddy current loss will cause the local temperature rise of the electric machine and the decrease of the overall efficiency of the electric machine. SUMMARY

[0005] One of the purposes of the present application is to provide a low eddy current loss stator end structure which can meet the cooling efficiency of the winding end and reduce the end eddy current loss under high load design.

[0006] The technical solution adopted by the present application to solve the technical problem is: a low eddy current loss stator end structure, comprising a stator tooth pressure plate, a stator yoke pressure plate and an end cooler; the stator tooth pressure plate is a fan-shaped small section of self-adhesive silicon steel sheet, which is axially staggered and stacked during installation; the stator yoke pressure plate is a single-layer structure made of non-magnetic material or a double-layer structure made of magnetic material and a magnetic shielding layer, the magnetic shielding layer is made of stainless steel and covers the outside of the yoke pressure plate, the thickness of the magnetic shielding layer should be greater than the skin depth, the magnetic shielding layer is placed close to the winding end to offset the end leakage magnetic field through the eddy current induced by the magnetic shielding layer to reduce the overall loss of the yoke pressure plate; the end cooler is made of die-cast aluminum.

[0007] The low eddy current loss stator end structure has a plurality of end coolers which are evenly distributed around the stator end and are electrically connected between each end cooler.

[0008] The low eddy current loss stator end structure is characterized in that the stator tooth pressure plate is an integral circular structure with an axial thickness of 30 mm obtained by stacking 3 layers of fan-shaped small sections with a thickness of 10 mm.

[0009] The end portion cooler quantity is 27, and two of the end portion coolers are welded together after being installed in the circumferential direction.

[0010] The second purpose of the present application is to provide a motor with low end portion eddy current loss, which is composed of a stator and a rotor.

[0011] The present application has the following advantages: the stator tooth pressing plate of the present application is made of self-adhesive silicon steel sheet, and is preformed into a fan-shaped segment and is formed by staggered lamination; the yoke pressing plate is made of non-magnetic material or magnetic material with a shielding layer; and the end portion coolers are electrically connected. Even if the motor is designed with high load, the eddy current loss can be effectively reduced, the end portion cooling efficiency of the motor can be ensured, local overheating points can be prevented, and the overall efficiency of the motor can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 Fig. 1 is a structural schematic diagram of the present application;

[0013] Figure 2 Fig. 2 is a sectional view in the direction of A-A in Fig. 1; Figure 1

[0014] Figure 3 Fig. 5 is a structural schematic diagram of the segmented stator tooth pressing plate of the present application.

[0015] Figure 4 Fig. 6 is a structural schematic diagram of the overall structure of the present application.

[0016] The reference signs are as follows: 1, stator tooth pressing plate; 2, yoke pressing plate; and 3, end portion cooler. DETAILED DESCRIPTION

[0017] The specific embodiments of the present application are described below in combination with the drawings and examples, so that those skilled in the art can better understand the present application.

[0018] Reference is made to Figures 1 to 4 ​The end structure of the low eddy current loss stator disclosed by the application mainly comprises a stator tooth pressing plate 1, a stator yoke pressing plate 2 and an end cooler 3. The stator tooth pressing plate 1 is a self-adhesive silicon steel sheet preformed into a fan-shaped small section, which is axially staggered and stacked during installation. The stator yoke pressing plate 2 is a single-layer structure made of a non-magnetic material or a double-layer structure made of a magnetic material and a magnetic shielding layer. The magnetic shielding layer is usually made of a metal with good electrical conductivity, preferably stainless steel, which is covered on the outer side of the yoke pressing plate 2. The thickness of the magnetic shielding layer should be greater than the skin depth. The magnetic shielding layer is placed near the winding end portion, and the eddy current induced by the magnetic shielding layer is used to offset the end leakage magnetic field and reduce the overall loss of the yoke pressing plate. The end cooler 3 is made of a high-thermal-conductivity metal material, preferably die-cast aluminum. The end cooler 3 is usually distributed around the circumference of the stator end portion, and each end cooler 3 should be electrically connected. The stator tooth pressing plate 1 is an integral circular structure with an axial thickness of 30 mm. During processing, the punching and stacking are first performed to form a fan-shaped small section with an axial thickness of 10 mm. During installation, the three layers are axially staggered. The end cooler 3 is made of die-cast aluminum, and there are 27 in the circumferential direction. After installation, two adjacent end coolers 3 are welded together.

[0019] The second purpose of the application is to provide a motor with low end eddy current loss, which is composed of a stator and a rotor. The stator has the above-mentioned end structure.

[0020] Compared with the background art, the motor with low end eddy current loss disclosed by the application solves the problem of high-load motor winding end eddy current loss, ensures the cooling effect of the winding end portion, prevents local overheating of the motor and improves the efficiency of the motor, and can be widely applied in the field of motors.

[0021] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto. Any changes or substitutions within the scope disclosed by the application can be easily thought of by those skilled in the art, and should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A low eddy current loss stator end structure characterized by: It comprises stator tooth pressing plate (1), stator yoke pressing plate (2) and end cooler (3), the stator tooth pressing plate (1) is segmentally arranged fan-shaped self-adhesive silicon steel sheet, and is installed in axial staggered manner, the stator tooth pressing plate (1) is obtained by pressing 3 layers of fan-shaped small segment punching sheet with thickness of 10 mm to obtain whole circular structure with axial thickness of 30 mm, the stator yoke pressing plate (2) is single-layer structure made of non-magnetic material or double-layer structure made of magnetic material and stainless steel magnetic shielding layer, the magnetic shielding layer is covered on the outer side of the yoke pressing plate (2) and is close to the winding end portion, the thickness of the magnetic shielding layer is greater than the skin depth, the magnetic shielding is arranged close to the winding end portion side, and the eddy current generated by the magnetic shielding layer is used to offset the end leakage magnetic field and reduce the overall loss of the yoke pressing plate, the end cooler (3) is die-cast aluminum, and the end cooler (3) is evenly distributed at the circumference of the stator end portion, and the end coolers (3) are electrically connected.

2. A low eddy current loss stator end turn structure according to claim 1, wherein, The number of the end coolers (3) is 27, and the end coolers (3) are welded together after being installed along the circumferential direction.

3. A low end part eddy current loss motor characterized by, It is composed of a stator and a rotor, and the stator has the end structure of claim 1.

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