JPH0442743A - Rotor structure for synchronous motor - Google Patents

Abstract

PURPOSE:To improve reliability in the prevention of peel off of a magnet by an arrangement wherein a dovetail made in the rotor core holds a magnet retaining member at a rotor core in order to resist against centrifugal force. CONSTITUTION:Magnets M1-M4 are applied onto the outer circumference of a rotor core 10 comprising a multiplicity of electromagnetic steel boards and magnet retaining members G1-4 are disposed between the magnets in the circumferential direction. A cross line P1 between the side face S1 and the outer face of the magnet M1 is shifted by an angle theta from a line L1 passing through the center of rotation CL of a rotor. A dovetail 12 is made in the surface 10 of rotor core between adjacent magnets. The magnet retaining members G1-4 made of nonmagnetic material such as aluminum or plastic, having profile suitable for filling the gap between the opposite side faces S1, S2, are then inserted in order to retain each magnet.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a synchronous motor rotor of a type in which a magnet is attached to the surface of a rotor core.

[Conventional technology]

In the above-mentioned type of rotor, the magnets have conventionally been fixed to the surface of the rotor core only with an adhesive, but the magnets have sometimes peeled off when the rotational speed is high. In order to prevent this, attempts have been made to wrap wire around the outer circumference of the rotor to prevent the magnets from peeling off due to centrifugal force.

[Problem to be solved by the invention]

However, since the gap between the rotor and the stator is small and the wires cannot be overlapped, the wires cannot be tied and connected, and there are many problems such as termination of the wires.

Therefore, an object of the present invention is to provide a highly reliable structure for preventing peeling of magnets in a type of rotor in which magnets are attached to the surface of a rotor core.

[Means to solve the problem]

In view of the above object, the present invention provides a structure of a synchronous electric motor rotor in which a magnet is attached to the surface of the rotor core,
The radius line of the rotor passing through the intersection line of the side surface of each magnet along the longitudinal direction of the magnet and the surface of the magnet is more circular than the radius line of the rotor passing through the side line at a smaller radius position. The surface portion of the rotor core in the region between the adjacent magnets is formed to move away from the opposing side surfaces of the adjacent magnets in the circumferential direction, and the surface portion of the rotor core in the area between the adjacent magnets is formed into a dovetail groove, and the rotor core is engaged with the dovetail groove and is formed so as to extend between the opposing side surfaces of the adjacent magnets. A structure of a synchronous electric motor rotor is provided, characterized in that it includes a magnet suppressing member formed to be filled.

Also, depending on the conditions, a surface portion of the rotor core in a region between adjacent magnets adjacent in the circumferential direction may be formed into a dovetail groove, and the surface portion of each magnet near the opposite side surface of the adjacent magnet may be engaged with the dovetail groove. To provide a structure of a synchronous electric motor rotor, characterized in that it is equipped with a magnetic holding member having a holding part for holding down a portion.

[For production]

In the former, a magnet holding member holds down each magnet via the side surface of each magnet to prevent movement of the magnet in the radial direction due to centrifugal force.

In the latter case, especially when there is sufficient clearance between the stator and the rotor, the magnet suppressing member presses each magnet from the surface.

In both cases, the dovetail groove formed in the rotor core holds the magnet holding member on the rotor core and resists centrifugal force.

〔Example〕

The present invention will be described in more detail below based on embodiments shown in the accompanying drawings.

FIG. 1 is a cross-sectional view of the rotor shown in FIG. 4 taken along arrow line I-I.
Magnets Ml, M2, M3 on the outer periphery of.

M4 is attached, and a magnet holding member G1. is attached between each magnet in the circumferential direction. G2゜G3. G4 is provided. Reference number 14 indicates the output shaft. Side surface S1 in the circumferential direction of the magnet) Ml and the side surface S1 of the magnet) Ml
A line L1 connecting the line of intersection (point in Figure 1) PL with the outer surface of the magnet M1 and the center of rotation CL of the rotor is a line L1 that connects the line of intersection (point in Figure 1) P2 with the inner surface of the magnet M1 and the rotation of the rotor. With respect to a line L2 connecting the magnet M1 with the center CL, the magnet M2 is shifted by an appropriate angle θ in the direction away from the opposing side surface S2 of the magnet M2. Also, the above magnet)
The slope of the side surface S2 of M2 is formed in a shape symmetrical to the side surface S1. Further, dovetail grooves 12 are formed in the surface portion of the rotor core 10 in areas between adjacent magnets. If this dovetail groove 12 is formed at the same time when punching and forming an electromagnetic steel sheet, the cost will not increase. Magnet suppressing members Gl, G2. Insert G3 and G4 from the longitudinal ends of the rotor, and attach each magnet to its side surfaces Sl and S.
2, it is possible to resist the centrifugal force and prevent the magnet from peeling off from the rotor core 10.

In the above embodiment, the entire side surface of each magnet is set at an appropriate angle θ.
However, if this cannot be adopted due to design constraints, as shown in Figure 2, each magnet M
The edges of the side surfaces Sl'S2' of L' and M2' are chamfered to form small inclined surfaces C1 and C2, and as in the above embodiment, the magnetic restraining member G' engaged with the dovetail groove 12 The magnet can be held down via the inclined surfaces C1 and C2.

FIG. 3 shows yet another embodiment.

In the case of this embodiment, it can be adopted when the gap size between the stator (not shown) and the outer surface of the magnet M1"M2" is relatively large, and the magnet holding member engaged with the dovetail groove 12 can be used. Presser section 16 at the upper edge of G''
The magnet M1''M2'' can be held down from its outer surface by the above.

Next, the order of assembling the rotor according to the present invention will be explained. Among the four dovetail grooves 12 of the rotor core 10, the magnet holding members Gl, G3 are inserted into and engaged with one dovetail groove selected at a time in the circumferential direction, and then the magnets Ml, M2. M3. While positioning M4 in the circumferential direction by pressing one side of each magnet against the side of magnet holding members Gl and G3,
Adhere to the outer surface of 0. And finally, the remaining magnet holding member G2. By inserting G4 into the dovetail groove,
Each magnet can be held down completely.

The assembly according to the above-mentioned order is particularly useful when a long rotor as shown in Fig. 4 has a configuration in which a plurality of magnets are arranged in parallel in the longitudinal direction. This is effective when a step is likely to occur in the side line of the magnet.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to provide a highly reliable structure for preventing magnet peeling off in a synchronous motor rotor in which a magnet is attached to the surface of the rotor core.

[Brief explanation of the drawing]

FIG. 1 shows a rotor structure according to the present invention, and is a cross-sectional view taken along arrow line I-I in FIG. 4. FIG. 2 is a partial view of a rotor structure according to a second embodiment of the present invention. FIG. 4 is a partial view of a rotor structure according to a third embodiment of the present invention. FIG. 4 is a side view of a rotor structure according to a third embodiment of the present invention. 10... Rotor core, 12... Dovetail groove, Gl, G2
．． G3. G4. G', G''... Magnet holding member, Ml, M2, M3, M4... Magnet.

Claims (1)

[Claims] 1. A structure of a synchronous electric motor rotor in which magnets are attached to the surface of a rotor core, wherein the side surface of each magnet and the side surface along the longitudinal direction of the rotor intersect with the surface of the magnet. The radius line of the rotor passing through the line is formed to be further away from the opposing side surfaces of circumferentially adjacent magnets than the radius line of the rotor passing through the side surface line at a smaller radius position, and the surface of the rotor core in the area between adjacent magnets. A structure of a synchronous electric motor rotor, characterized in that a portion thereof is formed into a dovetail groove, and a magnet holding member is formed to engage with the dovetail groove and fill between opposing side surfaces of the adjacent magnets. . 2. A structure of a synchronous electric motor rotor in which magnets are attached to the surface of the rotor core, in which the surface portion of the rotor core in the region between adjacent magnets adjacent in the circumferential direction is formed into a dovetail groove, and the rotor core is formed into a dovetail groove. A structure of a synchronous electric motor rotor, characterized in that the structure includes a magnet holding member having a holding part that presses a surface portion of each magnet near opposing side surfaces of the adjacent magnets.