Low-magnetic-flux-leakage high-strength rotor punching piece for electric vehicle permanent magnet motor

Abstract

The invention discloses a low-magnetic-flux-leakage high-strength rotor punching piece for an electric vehicle permanent magnet motor, which is simply referred to as a rotor punching piece 1. The rotor punching piece used in the invention is provided with magnetic steel grooves, connecting bands, transition arcs, weight reducing holes and a rotating shaft hole, and the connecting bands of the rotor punching piece are narrowed to reduce the magnetic flux leakage rate, and at the same time, parabolic transition arcs are arranged in the magnetic steel grooves connected with the connecting bands,so that the force bearing point of the centrifugal force is collected at the focus of the parabolic transition arcs to enhance the strength of the connecting bands and to avoid damage due to the force, and the electric vehicle permanent magnet motor achieves the purpose of reducing the magnetic flux leakage rate, increasing the output power, increasing the strength, and reducing the cost without increasing the shape and cost.

Description

Technical field [0001] The invention relates to a drive motor for an electric vehicle, in particular to a low-leakage and high-strength rotor punching sheet of an electric vehicle permanent magnet motor used for lamination to form an electric vehicle permanent magnet motor rotor. Background technique [0002] Explanation: The rotor punching piece described in this article is a sheet-shaped, alloy-permeable soft magnetic member that is laminated to form the rotor of an electric vehicle permanent magnet motor. The soft magnet is a magnetic material with low coercivity and high permeability. The rotor punching piece is provided with through holes into which permanent magnets are embedded, which is called a magnet slot, and the permanent magnets are also called magnets; [0003] Refer to the Chinese patent application, an electric vehicle permanent magnet motor rotor punching piece 201711501021.1. The rotor punching piece of the prior art is evenly distributed along the circumference w...

AI Technical Summary

Problems solved by technology

In practical application, the permanent magnet motor rotor made of the prior art rotor punching has a high flux leakage rate. In order to meet the improvement of the output power of the permanent magnet motor, the prior art has the following methods: for example, increasing the shape of the permanent magnet motor , that is, increasing the axial length of the rotor, correspondingly increasing the length of the magnetic steel and the axial length of the stator, the disadvantages are that the cost of the permanent magnet motor is increased, and the weight of the permanent magnet motor is increased. The increase in weight will increase the weight of the electric vehicle. Operating energy consumption; as another example, reduce the magnetic flux leakage rate; studies have shown that if the width of the connecting band is narrowed, the magnetic flux leakage rate can be effectively reduced, thereby increasing the output power of the permanent magnet motor without increasing the cost. , when the permanent magnet motor is working, the rotor speed is as high as 12,000 rpm. At such a high speed, the centrifugal force generated by the magnetic steel will deform or even damage the rotor cylinder with a narrow width of the connecting belt; To bear the centrifugal force during high-speed rotation and widen the connecting band, the widening of the connecting band makes the magnetic flux leakage rate of the permanent magnet motor rotor made of the prior art rotor punching high; therefore, the prior art There are problems and deficiencies such as high magnetic flux leakage rate, difficulty in increasing output power, and high cost

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