Magnetic yoke for bonded magnet motor

Abstract

Provided is a magnetic yoke of a bonded magnet motor that can achieve stable rotation performance without reducing centrifugal force resistance of a rotor rotating at high speed. A magnetic yoke (10) of a bonded magnet motor includes: a circumferential division yoke portion (11) that is divided in a circumferential direction; a radial side division yoke portion (12) that is divided in a radial direction and is movable in a radial direction; and a core pressing portion (13) that faces a rotor core, the core pressing portion (13) being integrally installed to the radial side division yoke portion (12).

Description

Technical Field

[0001] This utility model relates to the magnetic yoke of a bonded magnet electric motor. Background Technology

[0002] Patent document 1 describes an electric motor in which the main magnet is a sintered magnet and the auxiliary magnet is a bonded magnet. In the orientation forming of the bonded magnet, a magnetic field is applied to the workpiece in advance to form the magnetization direction of the magnetic powder so that it becomes a strong magnet.

[0003] [Existing Technical Documents]

[0004] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2006-149059 Summary of the Invention

[0006] [The problem that the utility model aims to solve]

[0007] However, due to the forming pressure of the bonded magnets, the rotor core undergoes bridge deformation, resulting in tensile stress. Consequently, the rotor's resistance to centrifugal force decreases at high speeds. Furthermore, the presence of an oriented magnetic yoke around the rotor core makes it impossible to install a sliding core.

[0008] [Methods used to solve problems]

[0009] One embodiment of the bonded magnet motor has a yoke having a circumferentially divided yoke portion divided in the circumferential direction and a radially divided yoke portion divided in the radial direction. The radially divided yoke portion is radially movable and is integrally mounted with the core pressing portion.

[0010] [Utility Model Effect]

[0011] According to the yoke of the bonded magnet motor disclosed herein, stable rotational performance can be obtained without reducing the centrifugal force resistance of the rotor rotating at high speed. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view showing an example of the magnetic yoke of the bonded magnet motor of Embodiment 1.

[0013] Figure 2 This is a diagram showing an example of the magnetic flux density of the yoke of the bonded magnet motor of Embodiment 1.

[0014] Figure 3 This is a perspective view showing an example of the radius-side segmented magnetic yoke 12 in Embodiment 1. Detailed Implementation

[0015] Implementation Method 1

[0016] The embodiments of this utility model will now be described with reference to the accompanying drawings. Figure 1 This is a cross-sectional view showing an example of the magnetic yoke of the bonded magnet motor of Embodiment 1. Figure 1 The quarter-scale model of the magnetic yoke is actually formed in the same roughly circular shape. Figure 1 In the middle, the magnetic yoke 10 has a circumferentially divided magnetic yoke portion 11, a radially divided magnetic yoke portion 12, a core pressing portion 13, and a coil 14.

[0017] The circumferentially divided yoke 11 is a yoke that is divided in the circumferential direction. Here, the circumferential direction refers to the circumferential direction of the circle traced by the rotation of the bonded magnet motor.

[0018] The radius-segmented yoke 12 is a yoke that is segmented in the radial direction. The radius-segmented yoke 12 is movable in the radial direction. Here, the radial direction refers to the radial direction of the circle traced by the rotation of the bonded magnet motor.

[0019] The core pressing part 13 is a component facing the rotor core 20. The core pressing part 13 is made of a non-magnetic material. For example, the core pressing part 13 is preferably made of SUS304, aluminum, or copper. The core pressing part 13 is integrally mounted on the side of the radius-side divided magnetic yoke 12 that contacts the rotor core 20. Furthermore, the rotor core 20 and the radius-side divided magnetic yoke 12 are configured to press the rotor core. In addition, the rotor core 20 has a bonding magnet 21 inside.

[0020] The coil 14 is wound with wire and generates magnetic force when energized.

[0021] Figure 2 This is a diagram illustrating an example of the magnetic flux density of the yoke in the bonded magnet motor of Embodiment 1. The division positions of the circumferentially divided yoke portion 11 and the radially divided yoke portion 12 are at... Figure 2 The C region with low magnetic flux density is preferred. Additionally, in... Figure 2 In the middle, the core pressing part 13 preferably has a notch or recess with a low magnetic flux density, D.

[0022] Figure 3 This is a perspective view showing an example of the radius-side segmented magnetic yoke 12 in Embodiment 1. (See diagram below.) Figure 3 As shown, by integrally installing the radius-side split magnetic yoke 12 and the core pressing part 13, the bridge part of the rotor core will not expand due to the forming pressure during the orientation forming process of bonding magnets, and the allowable stress will not decrease.

[0023] Thus, the yoke of the bonded magnet motor according to Embodiment 1 can achieve stable rotational performance without reducing the centrifugal force resistance of the rotor rotating at high speed.

[0024] Furthermore, this invention is not limited to the above-described embodiments and can be appropriately modified without departing from the main idea. For example, magnetic flux can be efficiently directed to the rotor core by filling a magnetic ring between the yoke and the rotor core. Additionally, if the air gap surface between the radius-side segmented yoke portion 12 and the rotor core 20 is set to be equal to or slightly different from the air gap surface between the core pressing portion and the rotor core 20, the air gap can be reduced, resulting in efficient magnetic flux flow to the rotor core.

[0025] [Explanation of reference numerals in the attached figures]

[0026] 10 Magnetic yoke

[0027] 11 Circularly divided magnetic yoke section

[0028] 12 Radius-side segmented magnetic yoke

[0029] 13-core pressing section

[0030] 14 coils

[0031] 20 Rotor cores

[0032] 21. Bonded magnets.

Claims

1. A yoke for a bonded magnet electric motor, characterized in that, have: The circumferentially divided magnetic yoke is divided in the circumferential direction; The radially segmented yoke is divided in the radial direction and is movable in the radial direction; and The core pressing section faces the rotor core. The core pressing part is integrally installed on the radial side segmented magnetic yoke part.

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