JPH0687632U - Super high speed rotor - Google Patents

Abstract

(57) [Abstract] [Purpose] When tightening a permanent magnet rotor on a rotating shaft that rotates at an extremely high speed, use a conical spring-type washer and a ball joint nut to prevent distortion during tightening and to prevent Prevent loosening. [Structure] Step 11 and screw portion 12 made of steel on the rotating shaft
The permanent magnet rotor 2 having side plates 22 and 23 and having a negative coefficient of thermal expansion is tightened by a ball joint type nut 4 via a washer 3 of a conical spring type. The surface on the side of 4 is formed into a concave spherical surface so that it fits into the convex surface of the nut 4 and the axial force at the time of tightening is uniformly transmitted. For this reason, the accuracy error of the end surface of the rotor 2 and the screw structure is not absorbed, the rotating shaft 1 is not bent, and the washer is used for the displacement when the temperature rises due to the difference in the thermal expansion coefficient between the steel material and the permanent magnet. Rotating axis 1
Absorbed by.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an ultra-high speed rotor of a rotary electric machine mounted on a turbine shaft of a turbocharger.

[0002]

[Prior art]

 In recent years, turbochargers that use the exhaust energy of the engine to increase the intake pressure of the engine have been widely used.A rotary electric machine is attached to the turbine shaft of this type of turbocharger to operate as an electric motor depending on the operating condition of the engine. It is operated or operated as a power generator to increase engine torque and recover exhaust energy.

Since such a turbocharger with a rotating electric machine rotates at an ultra-high speed of, for example, 100,000 rpm or more, a rotor made of a permanent magnet together with a thrust bush, a sleeve, etc. is attached to a nut with a stepped rotary shaft. A proposal of tightening and fixing with a rotary electric machine is disclosed in Japanese Utility Model Publication No. 4-93727 as a rotating body of a turbocharger with a rotating electric machine.

[0004]

[Problems to be solved by the device]

 In order to increase the magnetic force in the rotating body shown in the above-mentioned publication, when a neodymium-iron-baron permanent magnet is used for the rotor, since the direction perpendicular to the magnetic pole has a negative linear expansion coefficient, There is a large difference in the coefficient from the rotating shaft made of steel, and even if the rotor is mounted on the rotating shaft and the nut is tightened at room temperature, a relative change occurs due to the temperature rise during operation and the nut loosens due to the decrease in axial force. However, there is a problem that high speed driving causes danger.

Further, since the rotary shaft has a screw structure in the middle, it is affected by the inclination of the screw portion with respect to the rotary shaft and the accuracy error of parallelism of the rotor end face, and when the nut is strongly tightened, the rotary shaft bends, This is an obstacle to precise balance correction. Especially, since the rotation axis of the turbocharger with rotating electric machine is a long rotating body, the axial bending is a big problem.

The present invention has been made in view of such conventional problems, and an object thereof is to prevent a decrease in axial force even in a high temperature state during operation, and to have the above-described accuracy error. It is to provide an ultra-high speed rotor that tries to eliminate the bending of the rotating shaft.

[0007]

[Means for Solving the Problems]

 According to the present invention to achieve the above-mentioned object, in an ultra-high-speed rotor which is a permanent magnet rotor having an anisotropic linear expansion coefficient for a rotating electric machine, which is nut-fastened to a rotating shaft of a turbine rotating at an ultra-high speed, Tighten with a conical spring type washer having a concave spherical surface formed on the nut side interposed between the rotor and the nut, and a nut having a convex surface corresponding to the concave spherical surface on the contact surface with the washer. A super high speed rotor is provided.

[0008]

[Action]

 When tightening the rotor of a permanent magnet onto the rotating shaft of steel that rotates at high speed, a conical spring washer with a concave spherical surface on the nut side was used and a ball joint nut with a convex surface was used. The elastic force of the washer reduces the spring constant of the rotating shaft, which absorbs the displacement due to the difference in the coefficient of thermal expansion at high temperature to retain the axial force, and because the washer and the nut are more familiar. The axial force is evenly transmitted and the accuracy error is absorbed to prevent deformation of the rotating shaft.

[0009]

【Example】

 Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a rotor of an embodiment of an ultra-high-speed rotor according to the present invention and its related parts, and FIG. 2 is a side view of a rotor of a turbocharger with a rotary electric machine to which this embodiment is applied. Is.

In these drawings, reference numeral 1 denotes a rotary shaft made of high-strength steel material, which rotates at an ultrahigh speed of 100,000 rpm or more due to exhaust energy, and between a step 11 and a screw portion 12 at a predetermined position thereof. The rotor 2 is tightened.

The rotor 2 is a magnet rotor of an electric mechanism, which is required to have a strong magnetic force, and is made of, for example, a neodymium-iron-baron permanent magnet, and its peripheral wall portion withstands a centrifugal force during ultra-high speed rotation. A sleeve 21 made of CFPR is fitted, and side plates 22 and 23 made of a high-strength material are arranged on both end faces and fastened to the rotary shaft 1 by a washer 3 and a nut 4.

The washer 3 is of a conical spring type, its right side, that is, the nut side is provided with a concave surface of a spherical surface having a predetermined radius, and the nut 4 is a ball joint type. A convex surface corresponding to the concave surface is formed on the tightening surface. Therefore, when the rotor 2 is fastened to the rotating shaft 1 by both of them, the convex surface of the nut 4 is smoothly brought into contact with the concave surface of the washer 3 and the elastic force of the washer 3 against the rotor 2 between the step 11 and the step 11 is increased. At the same time, the rotor 2 is tightened with a uniform axial force by screwing.

Next, the operation of the present embodiment having the above-described structure will be described. The rotor 2 attached to the rotary shaft 1 is moved in the direction of the step 11 by the nut 4 via the washer 3 of the conical spring type. Since it is tightened, the spring constant on the rotating shaft 1 side is effectively reduced by the elastic force of the washer 3, and the diagram moves to the dotted line shown in the displacement diagram of FIG. Therefore, the high temperature during operation absorbs the displacement due to the difference in the coefficient of thermal expansion between the rotary shaft 1 and the rotor 2, and the high axial force is maintained.

Further, in this embodiment, since the contact surfaces of the washer 3 and the nut 4 are formed in the concave surface and the convex surface corresponding to each other, the axial force is applied to the rotor in a familiar and uniform manner at the time of tightening. It is possible to absorb the squareness error of the end face of 2 and the accuracy error of the screw part, and it is possible to correct the precise balance after assembly without bending the rotating shaft 1 even if tightened tightly.

2 is a turbine blade that is driven by receiving exhaust energy, and 6 is a compressor blade that is attached to the other end of the rotating shaft 1 by a tightening nut 61. Is rotatably supported at a very high speed by a floating bearing or the like arranged between the turbine blade 5 and the rotor 2.

Next, another example of preventing loosening due to the difference in expansion coefficient between the materials of the rotating shaft and the rotor in this embodiment will be described. When the material of the end plate 23 shown in FIG. 1 is a high thermal expansion metal, for example, a thermal expansion coefficient of 20 × 10 ⁻⁶ / C ° of a Ni alloy containing 20% of Fe base is used, neodymium-iron- Since the coefficient of linear expansion of the permanent magnet of boron is -18 × 10 ^-6 / C ° in the direction perpendicular to its magnetic pole, this is offset, and it is possible to prevent a decrease in axial force and loosening of screws. The present invention has been described in detail above with reference to the above-mentioned embodiments, but various modifications can be made within the scope of the present invention, and these modifications are not excluded from the scope of the present invention.

[0017]

[Effect of device]

 According to the present invention as in the above-described embodiment, when a permanent magnet rotor having an anisotropic linear expansion coefficient is attached to the rotating shaft of a steel material of a turbocharger that rotates at high speed, a conical spring type washer is used. Since the ball joint nut is used to tighten it tightly, the displacement due to the difference in the coefficient of linear expansion when the temperature rises is absorbed by the rotating shaft with the smaller spring constant, and the decrease in axial force is avoided. Even when a high thermal expansion metal is used for the side plate of the rotor to compensate for the difference in linear expansion coefficient, the displacement when the temperature rises is canceled out, and the decrease or loosening of the axial force is prevented. Further, in the present invention, since the washer surface facing the ball joint nut is a concave spherical surface, the axial force when the nut is tightened is transmitted uniformly, the accuracy error of the rotor and the screw part is absorbed, and the bending of the rotating shaft is suppressed. The effect of being prevented is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a rotor-related portion of an embodiment of an ultrahigh-speed rotor according to the present invention.

FIG. 2 is a side view of a rotor of a turbocharger with a rotating electric machine to which the present embodiment is applied.

FIG. 3 is a diagram showing the relationship between axial force and displacement in this embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rotating shaft 2 ... Rotor 3 ... Washer 4 ... Nuts 22, 23 ... Side plate

Claims (2)

[Scope of utility model registration request] 1. An ultra-high-speed rotor that is a permanent magnet rotor having an anisotropic linear expansion coefficient for a rotating electric machine, which is nut-fastened to a rotating shaft of a turbine rotating at an ultra-high speed. An ultra-high speed characterized by being tightened by a conical spring-type washer having a concave spherical surface formed on the nut side therethrough and a nut having a convex surface corresponding to the concave spherical surface on the contact surface with the washer. Rotor. 2. A side plate having a coefficient of thermal expansion for supplementing a difference in coefficient of thermal expansion between the rotary shaft and the permanent magnet material is interposed between the rotor and the washer.
The described ultra high speed rotor.