JPS62213538A - Rotor of synchronous motor - Google Patents

Abstract

PURPOSE:To prevent a peak torque from reducing due to an armature reaction magnetomotive force by cutting the portion of a pole piece except the route of a main magnetic flux in a triangular shape, and forming a wedge-shaped cutout at the pole piece, thereby alleviating the superposition of a rotor. CONSTITUTION:A pole piece (rotor core) (a) has a circular-arc surface 6, and is cut in a triangular shape except a portion that a magnetic flux is concentrated by a main magnetic flux passing therethrough to alleviate the superposition of a rotor core. A wedge-shaped cutout is formed at the extension of the triangular-shaped cut portion to enhance the magnetic resistance of a magnetic path for passing an armature reaction magnetomotive force so that the magnetic path is not saturated by the magnetomotive force to reduce the peak torque of a motor. Further, projections 3, 4 are formed on the axial center and air gap sides of each rotor core, and a permanent magnet (b) is disposed between the projections 3 and 4 of the adjacent rotor core.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotor for a synchronous motor used in an AC servo motor or the like.

(Prior Art) A servo motor is installed as a drive source for a load in a robot or a machine tool using a numerical control device (NC device). As for this servo motor, DC servo motors are often used because they are low in cost and have easy-to-configure control devices. However, since DC servo motors have a mechanical commutation mechanism, contact between the brush and commutator surface is Regular inspection and maintenance is required, such as adjusting pressure, removing brush wear particles, and replacing brushes. For this reason, AC servo motors, which are maintenance-free, have been used in various fields. this house,
AC servo motors using rust-conducting motors have the advantage of being able to control constant output in high-speed ranges, but have the problem that the control device becomes quite complex because it has to detect slippage and control the speed. There is. Therefore, with the development of high-performance magnetic materials such as samarium cobalt magnets, magnet-rotating synchronous motors are increasingly being used as AC servo motors.

(Points to be solved by the invention) Magnet rotating type JD used as an AC servo motor
The rotor of the Ha motive had a structure as shown in Fig. FJ4 and Fig. 5.

In FIG. 4, a plurality of alternating layers of permanent magnets are fixed to a shaft C. Further, in FIG. 5, magnetic pole pieces (rotor core) a and permanent magnets are alternately arranged and fixed on a shaft c, and the structure is of a magnetic flux concentration type. With such a magnetic flux concentration type configuration, (1) it is easy to design the magnetic flux density of the gap between the rotor and stator to an optimal value; (2) the magnets are surrounded by the rotor core; As AC servo motors, magnetic flux concentrated type Magnet type synchronous motors are often used.

However, in this type of synchronous motor, since the rotor core portion forms an armature reaction magnetic path, there is a problem that the core is saturated and the peak torque of the motor is reduced. One object of the present invention is to solve the problems of the prior art, and to provide a rotor for a synchronous motor that is light in weight and prevents a decrease in peak torque due to armature reaction magnetomotive force.

(Means for Solving the Problems) The present invention provides a plurality of magnetic pole pieces each having an arcuate surface facing a stator core through an air gap, arranged alternately with the magnetic pole pieces, and arranged on the axis side of the magnetic pole pieces and the air gap. In a permanent magnet supported between protrusions formed on the side in the rotational direction, the part other than the main magnetic flux path of the pole piece is cut into a triangular shape, and
The problems of the prior art described above are solved by providing a rotor for a synchronous motor, characterized in that wedge-shaped notches are formed in the magnetic path where the armature reaction magnetomotive force is generated.

(Function) The rotor of the synchronous motor of the present invention is produced by cutting the portion of the magnetic pole piece other than the main magnetic flux path into a triangular shape and forming wedge-shaped cuts in the magnetic path that generates the armature reaction magnetomotive force. , reduce rotor weight and improve torque characteristics.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of the rotor magnetic poles of the present invention.

As shown in the figure, the magnetic pole piece (rotor core) has a circular arc surface (6
), except for the part where the main magnetic flux passes through and concentrates the magnetic flux.
The hatched area (2) is cut into a triangular shape to reduce the weight of the rotor core. In addition, the rotor core has a wedge-shaped cut in the extension of the triangular cut part.
By increasing the magnetic resistance of the magnetic path that passes the armature reaction magnetomotive force,
Prevent the peak torque of the motor from decreasing due to saturation of the magnetic path due to armature reaction magnetomotive force.

Furthermore, the axis side (4) and the gap side (3) of each rotor core
By providing a protrusion in the direction of rotation and placing a permanent magnet between the protrusions (3) and (4) of adjacent rotor cores, the permanent magnets can move the rotor by centrifugal force without using a holding plate. Avoid leaving the core.

FIG. 2 is a diagram showing the arrangement relationship between the stator and the rotor of the present invention. In addition, Fig. 3 is a characteristic diagram showing the relationship between current and output torque. Current/torque curve when there is a wedge-shaped notch, (C) is the current/torque curve when there is no wedge-shaped notch.
This is a torque curve. This characteristic curve shows that the rotor structure of the present invention improves the current/torque characteristics.

(Effects of the Invention) As described above, according to the present invention, the portion of the magnetic pole piece other than the main magnetic flux path is cut into a triangular shape to reduce the weight of the rotor, and
By providing a wedge-shaped cut in the magnetic pole piece, it is possible to prevent a decrease in peak torque due to armature reaction magnetomotive force and improve torque characteristics.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of the main parts of the rotor of the present invention, Figure 2 is an overall layout diagram of the stator and rotor, Figure 3 is a characteristic diagram, Figures 4 and 5.
The figure is a configuration diagram of a conventional rotor. a...Magnetic pole piece, b...Permanent magnet, C...Shaft. Patent applicant Director of the Agency of Industrial Science and Technology Todoroki Handwriting Figure 1 (f) Figure 2 Cσ Figure 4 Figure 5

Claims (1)

[Claims] A plurality of magnetic pole pieces each having an arcuate surface facing the stator core through an air gap, arranged alternately with the magnetic pole pieces and supported between protrusions formed in the rotational direction on the axis of the magnetic pole piece and on the air gap side. A synchronous motor made of permanent magnets, characterized in that a portion of the magnetic pole piece other than the main magnetic flux path is cut into a triangular shape, and a wedge-shaped cut is formed in the magnetic path where armature reaction magnetomotive force is generated. rotor.