JPH0570149U - Ultra high speed motor rotor - Google Patents

Abstract

(57) [Summary] [Configuration] Thick steel plates 2 are arranged at both ends of the rotor core 1,
A thin plate stacking group 4 formed by stacking a plurality of thin plate stacked steel plates 3 made of the same material as the thick plate steel plate 2 and the thick plate steel plates 2 are alternately arranged between the two thick plate steel plates 2, 2 to form a shaft. A rotor core 1 is formed by laminating by applying a directional pressure, and the rotor core 1 is fixed to the rotor shaft 8 by shrink fitting. [Effect] Even if the laminated steel sheets are conventionally used such as silicon steel sheets, the adjacent laminated steel sheets are pressed against each other in the axial direction, so that the laminated steel sheets do not shift in the radial direction, and ultra-high speed rotation is achieved. Can bear.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a laminated structure of rotor cores in a small motor that rotates at an extremely high speed.

[0002]

[Prior Art]

 In a small ultra-high speed motor that drives a small turbo compressor etc. and rotates at an ultra high speed of 100,000 rpm, a rotor core is formed by laminating a plurality of annular laminated plates made of thin silicon steel plates like a normal motor. When the rotor steel was fitted to the rotor shaft to form a rotor, the tensile strength of the silicon steel plate was low, and the laminated plate was easily broken by the centrifugal force at high speed rotation, limiting the allowable number of rotations of the rotor. Further, when the rotor having a diameter of about 10 mm rotates at an extremely high speed, the resonance point becomes close, so that even the slight vibration may cause the rotor core to bend. As a result, the tightening margin between the laminated plate and the rotary shaft is reduced, the laminated plate is displaced in the radial direction, the balance is lost, and further large vibration may be generated. Conventionally, in order to prevent the adverse effect of centrifugal force at ultra-high speed rotation, a laminated high-speed motor has a high tensile strength and a laminated plate made of amorphous magnetic material with excellent magnetic properties, and a maraging steel with a larger longitudinal elastic modulus. It is possible to prevent the centrifugal force from breaking the laminated plate and reduce the tightening margin by increasing the strength of the laminated plate by forming a rotor for an ultra-high-speed motor by mixing and laminating laminated plates made of metal such as In addition, a material that reduces iron loss is disclosed (for example, Japanese Patent Laid-Open No. 122322/1989).

[0003]

[Problems to be solved by the device]

 However, in the above configuration, the cost of the rotor material is high because two different materials such as an expensive amorphous magnetic material and maraging steel must be used for the laminated plate. Further, when the laminated plate is formed, the strength of the material is high, so that there is a large wear of the punching die during processing by a press, resulting in a large number of processing steps. An object of the present invention is to provide an inexpensive and compact ultra-high speed motor rotor that can withstand ultra-high speed rotation by using a laminated plate made of the same material as the conventional one, such as a silicon steel plate.

[0004]

[Means for Solving the Problems]

 The present invention is a rotor for a small ultra-high speed motor in which a plurality of annular laminated steel plates are laminated to form a rotor core, and the rotor core is shrink-fitted to the rotor shaft to arrange thick steel plates at both ends. A thin plate stack group formed by stacking a plurality of thin plate steel plates made of the same material as the thick steel plate between two thick steel plates arranged at the both ends, and a thick steel plate made of the same material as the thick steel plate. Rotor cores are formed by alternately arranging them and applying axial pressure.

[0005]

[Action]

 Since the rotor core is made by alternately stacking thick steel plates and thin plate lamination groups, when the rotor is rotated at high speed, the thick steel plates have a larger iron loss than the thin laminated steel plates, and the secondary due to eddy currents on the rotor surface. Copper loss occurs. The temperature of the thick steel plate rises above the temperature of the thin laminated steel plate, and a large expansion force acts in the axial direction. Therefore, the thin laminated steel plates of the thin laminated group located between the thick steel plates are subjected to a force in the same direction as the axial pressure applied during lamination from the thick steel plates on both sides, and the adjacent thin laminated steel plates are The two are pressed against each other in the axial direction, and the frictional force between the thin laminated steel plates increases. Therefore, it is possible to prevent the thin laminated steel sheet from being displaced in the radial direction and reduce the tightening margin between the thin laminated steel sheet and the rotary shaft.

[0006]

【Example】

The present invention will be described with reference to the embodiments shown in the drawings. FIG. 1 is a side view showing an embodiment of the present invention, a part of which is shown in section. The rotor core 1 has a relatively thick annular steel plate 2, for example, a thick steel plate 2 having a thickness of about 2 to 5 mm, arranged at both ends of the rotor core 1. Between the thick steel plates 2 at both ends thereof, a plurality of annular laminated steel plates 3 having the same diameter as the thick steel plate 2 and having a relatively small thickness, for example, about 0.1 to 0.5 mm. The thin plate stacking groups 4 formed by stacking and the thick plate steel plates 2 are alternately arranged, and a pressure is applied in the axial direction to stack them. The thick steel plate 2 and the thin laminated steel plate 3 are provided with a plurality of through holes 5 at equal intervals in the circumferential direction, and the thick steel plate 2 and the thin laminated steel plate 3 are laminated in the shape of the rotor core 1 in a penetrating manner. A conductor 6 is fitted in the hole 5, and both ends of the conductor 6 are joined to short-circuit rings 7 provided on both end faces of the rotor core 1 to form a secondary conductor. The inner circumference of the rotor core 1 is shrink-fitted to the outer circumference of the rotor shaft 8 to form the rotor. When the rotor configured as described above is rotated at a high speed, the thick steel plate 2 has a larger iron loss and copper loss than the thin laminated steel plate 3, so that the temperature of the thick steel plate 2 rises above the temperature of the thin laminated steel plate 3. A large expansion force works in the axial direction. Therefore, the thin laminated steel plates 3 of the thin laminated group 4 located between the two thick steel plates 2 are subjected to a force from the thick steel plates 2 on both sides in the same direction as the axially applied pressure during the lamination. Is added, the adjacent thin laminated steel plates 3 are pressed in the axial direction, so that the frictional force between the thin laminated steel plates 3 increases. Therefore, since it is possible to prevent radial deviation of the thin laminated steel plate, even if the thin laminated steel plate has been conventionally used such as a silicon steel plate, there is little reduction in the tightening margin between the thin laminated steel plate and the rotary shaft. The thin laminated steel sheet will not lose its balance, and the thin laminated steel sheet will not be broken by centrifugal force at ultra-high speed rotation. Since the central portion of the rotor core 1 in the axial direction is difficult to cool and the vicinity of both end faces is easily cooled, as shown in Fig. 2, the central portion is laminated with a large number of thin laminated steel plates 3 with less iron loss and copper loss. and, for example, increasing the thickness of the lamination thickness t _1, by reducing the thickness w ₁ of the thick steel plate 2, the sequential thinning of the lamination thickness t _2, t ₃ ··· t _n of the thin laminated steel plate 3 as it goes to the end On the contrary, if the plate thicknesses w ₂ , w ₃ ... w _n of the thick steel plate 2 are successively increased and the copper loss and iron loss generated by the rotor are increased from the central portion toward the end portion, The temperature distribution of the rotor core becomes relatively uniform, thermal deformation due to uneven temperature distribution of the rotor is suppressed, and deterioration of the balance can be prevented.

[0007]

[Effect of the device]

 As described above, according to the present invention, since the rotor core is formed by alternately stacking thick steel plates and thin plate laminated groups, the laminated steel plates are adjacent to each other even though they are conventionally used such as silicon steel plates. Since the laminated thin steel sheets are pressed against each other in the axial direction and the laminated thin steel sheets do not shift in the radial direction, they can withstand ultra-high speed rotation. Furthermore, by changing the thickness of the thin plate stack and the thick steel plate in the axial direction, the iron loss and copper loss generated in the rotor are increased from the central part to the end part. Is relatively uniform, and deterioration of balance due to thermal deformation can be prevented. In addition, since the thick steel plate and the thin laminated steel plate can be formed of the same material, there is an effect that an economical rotor for a super high speed motor can be provided at a low cost with a small number of processing steps.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a side view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Rotor Core 2 Thick Steel Plate 3 Thin Laminated Steel Plate 4 Thin Laminate Group 8 Rotor Shaft

Claims (2)

[Scope of utility model registration request] 1. A rotor for a small ultra-high-speed motor in which a plurality of annular laminated steel plates are laminated to form a rotor core, and the rotor core is fixed to a rotor shaft by shrink fitting, and thick steel plates are arranged at both ends of the rotor. 2 placed on both ends
A thin plate laminated group formed by laminating a plurality of thin plate laminated steel plates of the same material as the thick plate steel plate between a plurality of thick plate steel plates and a thick plate steel plate of the same material as the thick plate steel plate are alternately arranged, A rotor for an ultrahigh-speed motor, characterized in that a rotor core is formed by applying a directional pressure. 2. The laminated thickness of the thin plate stacking group is reduced from the axial center of the rotor core toward the axially outer side, and conversely, the thickness of the thick steel plate is increased toward the axially outward side. The rotor for an ultra high speed motor according to claim 1, which is characterized in that.