JP2000152536A - Rotor of permanent magnet synchronous motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and reliably laminate the split fan-shaped cores of the rotor of a permanent magnet synchronous motor, including the case of a high-speed machine, and secure them on a rotor shaft at a prescribed position. SOLUTION: Studs 2, for securing rotor cores which maintain the intervals between two adjacent sets of rotor cores in the circumferential direction on both their sides 2b and 2c, have projected retaining portions 2a at both their ends in the circumferential direction and maintain radial position of the rotor cores 1 against exerted centrifugal force, and a pair of end plates, which are installed and secured on the rotor shaft in a specified circumferential and axial position, are formed. A pair of the end plates with the rotor core 1 laminated along the respective studs 2 of a number equivalent to the number of magnetic poles (four sets in the case of the figure) clamped between them is joined by tightening screws at the studs 2 and both their respective ends, to form a rotor of a permanent magnet synchronous motor comprising split fan-shaped rotor cores.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor of a permanent magnet synchronous motor formed by laminating and fixing a divided fan-shaped rotor core at a predetermined position on a rotor shaft circumference.

[0002]

2. Description of the Related Art Conventionally, as a rotor of a permanent magnet type synchronous motor of this kind, when a permanent magnet is to be retrofitted with a rotor core having an integral shape, shrink-fitting is inserted into the rotor shaft. When the rotor core is formed by laminating and fixing the rotor core at a predetermined position on the rotor shaft, or when the rotor core has a simple fan shape or an integral shape and a permanent magnet is embedded in the core, It is known that the rotor core is fixed by lamination and countermeasures against centrifugal force by a through bolt and a gap between laminated cores, and is also formed by fixing the core to a predetermined position on the rotor shaft circumference by a key. ing.

[0003]

Regarding the formation of the rotor of the permanent magnet type synchronous motor, first, shrink-fitting of the rotor core into the rotor shaft involves a high-temperature treatment step of the rotor core, and the permanent magnet is heated at a high temperature. Therefore, it is not applicable to the case where the permanent magnet is embedded and fixed in the iron core and the case where the rotor core forms a split fan shape, and only when the rotor core shape is integral and the permanent magnet is retrofitted. Therefore, the range of application is inevitably narrowed for various types of permanent magnet type synchronous motors.

[0004] Next, when the rotor core is fixed to the rotor shaft by a through bolt or the like, the flow of magnetic flux in the iron core is obstructed because a bolt hole is penetrated through the rotor core, so that predetermined electric characteristics are obtained. This limits the realization, and consequently, the increase in bolt diameter is restricted, and the application to a high-speed motor that requires an increase in bolt diameter due to an increase in centrifugal force acting on the rotor core is also restricted.

Further, in the conventional structure, it is very difficult to control the flow of magnetic flux in the rotor core to clarify the magnetic pole separation between adjacent magnetic poles, and it is difficult to control the ratio between the inductances of the q and d axes. It is difficult to make the saliency pole ratio, which defines the reluctance torque given by the above, about 2 or more.

In view of the above, the present invention relates to a rotor of a permanent magnet type synchronous motor formed by laminating and fixing a divided fan-shaped rotor core at a predetermined position on the circumference of a rotor shaft. Easy and reliable lamination fixation to the shaft enables application to high-speed machines, and also makes use of the characteristics of the split fan rotor core in the flow of magnetic flux more clearly to increase the salient pole ratio and reduce field control. It is an object of the present invention to provide a rotor of a permanent magnet type synchronous motor that enables effective use of reluctance torque by combining with a rotor.

[0007]

In order to achieve the above object, in a rotor of a permanent magnet type synchronous motor according to the present invention, 1) The invention according to claim 1 is divided into a number of poles to form a sector shape. A rotor of a permanent magnet type synchronous motor formed by laminating and fixing a divided rotor core on which a magnetized permanent magnet is disposed at a predetermined position on the rotor shaft circumference, between two adjacent fan-shaped cores. Holding member that functions as a spacing member that maintains the circumferential spacing of the fan-shaped core and that maintains the radial position of the fan-shaped core that has projections at both ends in the circumferential direction and supports it against centrifugal force that acts. A stud for fixing the rotor core functioning as a core, and a pair of end plates that are fixedly mounted on the rotor shaft by specifying their positions in both the circumferential direction and the axial direction, and the cores provided by the number of poles are provided. Each of the above stacked along studs for fixing The pair of end plates having a fan-shaped core sandwiched therebetween are formed by tightening and coupling to the studs at both ends of the studs for fixing the cores.

[0008] According to a second aspect of the present invention, in the rotor of the first aspect, the stud for fixing the iron core and the end plate are formed of a non-magnetic material. According to a third aspect of the present invention, in the rotor of the permanent magnet type synchronous motor according to the first aspect, the stud for fixing the iron core has screw portions for fastening and fixing the pair of end plates at both ends or one end thereof. Shall be.

As described above, according to the present invention, a projecting portion for maintaining the radial position of the fan-shaped core against opposing centrifugal force is provided at both ends in the circumferential direction of the spacing member disposed between two adjacent sets of fan-shaped cores. The spacing member is provided as a stud for fixing the rotor core, and the fan-shaped core is laminated using the stud as a guide, and the position is designated on the rotor shaft and is fixed between a pair of end plates. The fan-shaped iron core is sandwiched, and the pair of end plates are fixed to both ends or one end of each of the studs by screwing or the like. Further, the studs for fixing the rotor core are made non-magnetic so as to prevent the formation of a magnetic flux short-circuit path between adjacent magnetic poles, thereby clarifying magnetic pole separation.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a radial sectional view of a permanent magnet type synchronous motor rotor according to a first embodiment of the present invention corresponding to claim 1, and FIG. 2 corresponds to claims 1 and 3. FIG. 9 is an axial sectional view of the electric motor rotor showing a second embodiment of the present invention.
FIG. 6 is a radial sectional view of a stud for fixing a rotor core according to a third to an eighth embodiment of the present invention, which corresponds to claim 1 of the present invention.

First, in the radial cross-sectional view of the motor rotor shown in FIG. 1, reference numeral 1 denotes a rotor core which is divided into a fan shape, and 2 denotes a stud for fixing the rotor core 1 and its cross-sectional shape is simulated. This is shown in FIG. Reference numeral 2a denotes a protruding holding portion for maintaining the radial position of the rotor core 1 which is provided at both ends in the circumferential direction of the stud 2 and supports the centrifugal force acting thereon. Are the outer peripheral side and the inner peripheral side. FIG. 1 shows an example of a four-pole synchronous motor, and four sets of studs 2 are provided for the number of poles.

Although the arrangement of the permanent magnets in the rotor core 1 is not shown, for example, an arc-shaped recess is provided in the outer peripheral surface of each of the fan-shaped rotor cores 1 and an arc-shaped recess is formed therein. The permanent magnets are arranged by bonding and fixing the permanent magnets, or similarly by bonding and fixing an arc-shaped permanent magnet to the arc-shaped inner peripheral surface of the rotor core 1.

Next, in the axial sectional view of the motor rotor shown in FIG. 2, reference numeral 3 denotes a rotor shaft, and reference numeral 4 denotes a rotor shaft 3 whose positions in the circumferential direction and the axial direction are designated and fixed. A pair of end plates. As shown in the figure, the pair of end plates 4 sandwiching the rotor core 1 laminated along each of the studs 2 for fixing the iron core are screwed into nuts 6 and the like at screw portions 5 provided at both ends of each stud 2. To form a motor rotor. That is, by the studs 2 provided for the number of poles for fixing the iron core,
The tightening of the rotor core 1 and the fixing of the rotor core 1 to a predetermined position on the circumference of the rotor shaft 1 are performed via the pair of end plates 4 attached and fixed to a designated position on the rotor shaft 3.

FIG. 2 shows an example in which the rotor core 1 is fixedly mounted on the rotor shaft 3 via a pair of end plates 4, but the rotor core 1 is attached to the rotor core 1 like a high-speed motor. When the acting centrifugal force becomes large, an appropriate number of spacing plates having the same shape as the end plates are inserted between the pair of end plates to cope with the increase in the centrifugal force.

3 to 8 are sectional views of the stud for fixing the rotor core shown in FIG.
FIG. 1 and FIGS.
The studs 21 to 26 correspond to the stud 2 and the studs 21 to 26 correspond to the studs.
The holding portions 21a to 26a correspond to the protruding holding portion 2a, the side portions 21b to 26b correspond to the outer side surface portion 2b of the stud 2, and the side surface also corresponds to the inner side surface portion 2c. The parts 21c to 26c correspond.

As shown in the drawing, the boundary between the holding portion of each stud and both side portions is not necessarily so clearly distinguishable as in the stud 2 shown in FIG. 1 and is located at the mounting position of the stud in the radial direction of the rotor core. In order not to disturb the flow of the magnetic flux in the iron core by the corresponding permanent magnets arranged, at the same time, as having a shape capable of withstanding the centrifugal force acting on the rotor corresponding to the motor rotation speed, The stud having the optimum cross-sectional shape in the figure is selected.

[0017]

According to the present invention, there is provided a rotor of a permanent magnet type synchronous motor formed by laminating and fixing a divided fan-shaped rotor core at a predetermined position on the rotor shaft circumference. As described above, the rotor core maintains the circumferential distance between adjacent fan cores, and has the protruding portions at both ends in the circumferential direction to maintain the radial position of the fan core supporting against centrifugal force. A fixing stud and a pair of end plates whose mounting fixing positions are specified on the rotor shaft are provided, and the fan-shaped cores stacked along the studs provided for the number of poles are sandwiched between the studs. A high-temperature treatment such as shrink-fitting is performed at the time of assembling the rotor core by forming a motor rotor by fastening a pair of end plates with screws at, for example, both ends of the studs and tightening and coupling the studs to the studs. Without incident Therefore, the cross-sectional area of the stud can be increased without impairing the characteristics of the permanent magnet due to high temperature and without providing a through hole for a core tightening through bolt that hinders the flow of magnetic flux in the iron core. Since it is easy to cope with the acting centrifugal force, the lamination and fixing of the divided sector-shaped rotor core at a predetermined position of the rotor shaft can be performed easily and reliably for a wide range of permanent magnet synchronous motors including high-speed machines. Can be performed.

According to a second aspect of the present invention, in the rotor core structure having the configuration according to the first aspect, the stud for fixing the rotor core is made of a non-magnetic one and a magnetic flux short-circuit path between adjacent magnetic poles is formed. By using the characteristics as a split-type sector rotor core more clearly, the salient pole ratio is increased, and weakening is combined with field control to effectively utilize the reluctance torque. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a radial sectional view of a permanent magnet type synchronous motor rotor showing a first embodiment of the present invention.

FIG. 2 is an axial sectional view of a permanent magnet type synchronous motor rotor according to a second embodiment of the present invention.

FIG. 3 is a radial cross-sectional view of a stud for fixing a rotor core according to a third embodiment of the present invention.

FIG. 4 is a radial sectional view of a stud for fixing a rotor core according to a fourth embodiment of the present invention;

FIG. 5 is a radial cross-sectional view of a stud for fixing a rotor core according to a fifth embodiment of the present invention.

FIG. 6 is a radial cross-sectional view of a stud for fixing a rotor core according to a sixth embodiment of the present invention.

FIG. 7 is a radial sectional view of a stud for fixing a rotor core according to a seventh embodiment of the present invention;

FIG. 8 is a radial sectional view of a stud for fixing a rotor core according to an eighth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Stator core 2 Stud for fixing rotor core 2a Retaining portion 2b Outer side surface portion 2c Inner side surface portion 3 Rotor shaft 4 End plate 5 Screw portion 6 Nut 21 to 26 Stud for fixing rotor core 21a-26a Holder 21b-26b Outer side surface 21c-26c Inner side

Claims (3)

[Claims] 1. A permanent magnet synchronous machine formed by laminating and fixing a divided rotor core in which fan-shaped and magnetized permanent magnets divided in the number of poles are arranged at predetermined positions on the rotor shaft circumference. A rotor of an electric motor, which functions as a spacing member for maintaining a circumferential spacing between two sets of adjacent fan-shaped iron cores, and has centrifugal force acting with protrusions at both circumferential ends. A stud for fixing the rotor core, which functions as a holding member for maintaining the radial position of the sector core supported in opposition,
A pair of end plates whose positions in both the circumferential direction and the axial direction are specified and fixed on the rotor shaft are provided, and each of the sector shapes stacked along the core fixing studs provided for the number of poles is provided. A rotor for a permanent magnet type synchronous motor, wherein said pair of end plates having an iron core sandwiched therebetween are formed by tightening and coupling to said studs at both ends of said iron core fixing studs. 2. A permanent magnet synchronous motor according to claim 1, wherein said stud for fixing said iron core and said end plate are formed of a non-magnetic material. Rotor. 3. A rotor for a permanent magnet type synchronous motor according to claim 1, wherein said stud for fixing said iron core has screw portions for fastening and fixing said pair of end plates at both ends or one end thereof. A rotor of a permanent magnet type synchronous motor characterized by the above-mentioned.