JPH02119543A - Rotary electric machine for turbocharger - Google Patents

Abstract

PURPOSE:To prevent breakdown due to centrifugal force received by a cage type coil by covering the outer circumferential wall surface of a rotor with a metallic material having high tension. CONSTITUTION:The magnetic substance section 4a of a rotor 4 is formed of the laminating material of a ferromagnetic substance blank having excellent permeability, and a plurality of groove sections 4c are notched at regular intervals obliquely or in parallel to a central shaft in a columnar outer circumferential wall 4b. A thin cylinder 4d is composed of a metallic material covering the outer circumferential wall 4b and having high tension, and shaped of a SUS material called the so-called stainless or an amorphous material or the like. An end ring 4g is acquired by forming a blank having high conductivity such as a copper material in a ring-shaped disc, and the end rings are installed onto both side faces of the rotor 4. The number of revolution of a turbine is brought to one hundred thousands r.p.m or more in the rotor 4 of the rotary electric machine of a turbocharger constituted in this manner, but the outer circumferential wall is covered with the thin cylinder 4d consisting of the metallic material having high tension, thus resisting breakdown due to centrifugal force received by a cage type coil.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotating electric machine for a turbocharger driven by exhaust energy of an internal combustion engine.

(Prior art) In recent years, turbochargers have been widely used, which use the thermal energy of the exhaust gas of an internal combustion engine to rotate an exhaust turbine, drive a compressor directly connected to the exhaust turbine, and forcefully deliver supercharged air to the internal combustion engine. There is. The rotor of a rotating electrical machine that serves as an electric generator is attached to the rotating shaft of such a turbocharger, and the rotating electrical machine is driven by exhaust energy to generate electricity, or the rotating electrical machine is supplied with power from a battery to generate a turbo. A turbocharger with a rotating electric machine that assists the supercharging operation of the charger has been developed. The rotor of this type of rotating electric machine is installed on the rotating shaft of the turbocharger, so it rotates at high speed and there is a risk of destruction due to centrifugal force.

Therefore, a proposal was made in JP-A-62-25 to provide an outer cylinder on the peripheral wall of the rotor made of permanent magnets to prevent damage caused by centrifugal force, and to provide a heat insulating section between the turbine rotating shaft and the rotor.
It is described in Japanese Patent No. 4849 as a generator for a turbocharger.

(Problems to be Solved by the Invention) In the above proposal for a turbocharger generator, a permanent magnet is used in the rotor, so even if a heat insulating section is provided between the rotor and the turbine rotating shaft, long-term operation is not possible. Under the influence of high-temperature exhaust gas, the temperature of the permanent magnet increases and becomes demagnetized, resulting in a reduction in the efficiency of the rotating electrical machine.

On the other hand, squirrel cage type rotors do not use permanent magnets in the rotor, but the outer wall of the rotor is generally made of aluminum, which has low tensile strength, so the rotor will break due to centrifugal force under ultra-high speed rotation. The problem is that there is a possibility that

The present invention was made in view of these problems, and its purpose is to prevent the efficiency of a rotating electric machine from changing over time and to eliminate centrifugal force even when used as a rotor of a rotating electric machine for a turbocharger at ultra high speed rotation. An object of the present invention is to provide a rotating electric machine for a turbocharger that is sufficiently resistant to the above.

(Means for Solving the Problems) According to the present invention, squirrel cage coils are formed in a plurality of equally spaced grooves parallel to the cylinder axis, which are carved in the outer peripheral wall of a cylindrical layered ferromagnetic material. Provided is a rotating electrical machine for a turbocharger, comprising a rotor in which a good electrical conductor is buried, and the outer peripheral wall surface is covered with a thin cylinder made of a metal material having high tensile strength, covering the groove and the good conductor. can.

(Function) According to the present invention, since the rotor is a squirrel-cage coil rotor without using permanent magnets, it is possible to prevent the demagnetizing effect of magnetic force due to high temperatures, and the outer peripheral wall of the rotor is kept under high tension. Since the squirrel cage coil is coated with a metal material having the following characteristics, it has the effect of preventing destruction due to centrifugal force applied to the squirrel cage coil.

(Example) Next, an example of the present invention will be described in detail using the drawings.

FIG. 1 is a sectional view showing a turbocharger rotating shaft and rotor of a rotating electric machine for a turbocharger according to the present invention, and FIG. 2 is an explanatory view showing an example of the rotor.

In Fig. 1, reference numeral 1 denotes a rotating shaft of the turbocharger, which has turbine blades 2 and compressor blades 3 at both ends, bearings la and lb in the middle, and is rotatably supported by the main body of the turbocharger. There is.

4 is a hollow cylindrical rotor, and a rotating shaft 1 is installed in the hollow part.
is inserted and fixed to the rotating shaft 1, and operates as a generator or a motor in electromagnetic correspondence with a stator of a rotating electric machine, which will be described later.

Incidentally, in order to avoid the thermal influence of the exhaust gas conducted from the turbine blades 2, the rotor 4 is provided between the bearing 1b and the compressor blades 3.

FIG. 2(a) is a longitudinal sectional view of the rotor, and FIG. 2(b) is a perspective view showing the grooves of the rotor.
is made of a laminated material of ferromagnetic material with good magnetic permeability,
A plurality of grooves 4C are carved in the cylindrical outer peripheral wall 4b at equal intervals parallel to or obliquely to the central axis. Reference numeral 4d denotes a thin cylinder made of a metal material having high tension and covering the outer circumferential wall 4b, and is made of a SUS material called stainless steel, an amorphous material, or the like.

4f is a copper wire that forms a part of the squirrel-cage coil, and a wire material matching the cross-sectional shape of the groove 4c is inserted into the groove 4c, or molten copper is poured into the groove 4c, and the wire is inserted together with a short-circuit ring to be described later. A squirrel cage coil may also be formed.

FIG. 2(c) is an explanatory view showing one side of the rotor. In the same figure, 4g is a short-circuit ring, which is made of a highly conductive material such as steel and formed into a ring-shaped disc. It is provided on both sides. Then, as mentioned above, the molten copper material is formed with the copper wire 4f by vacuum suction, or in the case of a ring-shaped disk, holes are made at the corresponding positions of the copper wire 4f.
After inserting the end of the copper wire 4f, it is mechanically and electrically joined by brazing or the like.

FIG. 3 is a partially cutaway perspective view showing another embodiment of the rotor, in which a portion near the outer peripheral wall of a cylindrical magnetic body portion 4h made of laminated ferromagnetic materials with high magnetic permeability has a cylindrical axis. A plurality of holes parallel to the axis of rotation are cut at equal intervals on a circumference concentric with the rotation axis, and a copper rod 4j is inserted into each of these holes, and both ends of each copper rod 4j are connected to the magnetic body portion 4h. It is electrically connected to short circuit rings 4 provided on both sides to form a squirrel cage coil. The outer peripheral wall of the cylinder constituted by the magnetic body portion 4h and the short circuit ring 4k is covered with a thin cylinder 4d made of a high tensile strength material.

Incidentally, the squirrel cage coil may be formed by integrally forming the copper rod 4j and the shorting ring 4 by pouring molten copper, as in the case of the example shown in FIG. 2 described above.

FIG. 4 is a sectional view of an example of a turbocharger with a rotating electric machine to which these rotor embodiments are applied, and 6 is a stator corresponding to the rotor 4, which has a predetermined stator winding 6a. ,
When AC power is supplied to the stator winding 6a, the stator 4 is driven to rotate at a rotation speed corresponding to the frequency of the AC power, and the rotor 4 is driven at a rotation speed exceeding the rotation speed corresponding to the frequency. It becomes an induction generator and is configured so that electric power is induced in the stator winding 6a.

2a is an exhaust gas population, in which exhaust gas from an exhaust pipe of an internal combustion engine (not shown) passes through the inside of the turbine housing 2b, drives the turbine blades 2, and is discharged to the outside from the exhaust gas outlet 2c.

Reference numeral 3a denotes an intake air inlet, which compresses intake air within the compressor housing 3b by the rotation of the compressor blades 3, which are directly connected to the turbine blades 2 through the rotating shaft 1, and sends the supercharged air under pressure to the intake pipe of the internal combustion engine. be.

The rotor of the rotating electrical machine of the turbocharger configured in this way has a turbine rotation speed of 100,000 revolutions per minute or more, but the rotor shown as an example in FIGS. Since it is covered with a thin cylinder made of a metal material having tension, it can withstand destruction due to centrifugal force applied to a squirrel cage coil made of a conductive material such as steel.

Although the present invention has been described above using the above-mentioned embodiment, various modifications can be made within the scope of the gist of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) According to the present invention, since permanent magnets are not used in the rotor of the rotating electric machine of a turbocharger that rotates at extremely high speeds under high temperatures, there is no risk of efficiency reduction due to demagnetization effect, and the rotor Since the outer periphery is covered with a thin cylinder with high tension, it can withstand damage caused by centrifugal force even when used as a rotor of a rotating electric machine for a turbocharger at ultra high speed rotation.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a turbocharger rotating shaft and rotor to which the present invention is applied, FIG. 2 is an explanatory view showing one embodiment of the rotor, and FIG. 3 is a perspective view of another embodiment of the rotor. , FIG. 4 is a sectional view of an example of a turbocharger with a rotating electrical machine. DESCRIPTION OF SYMBOLS 1... Rotating shaft, 2... Turbine blade, 3... Compressor blade, 4... Rotor, 4a... Magnetic body part, 4c
...Groove, 4d...High tensile strength thin cylinder, 4f/4j/
...Copper wire, 4g/4k...Short ring, 6...Stator. Figure 1 Figure 2

Claims (3)

[Claims] (1) A good electrical conductor that will become a part of the squirrel cage coil is buried in a plurality of equally spaced grooves parallel to the cylinder axis carved into the outer circumferential wall of the ferromagnetic material stacked in a cylindrical shape, and 1. A rotating electric machine for a turbocharger, comprising a rotor whose outer peripheral wall surface is covered with a thin cylinder made of a metal material having high tension, covering a groove portion and a good conductor. (2) The rotating electrical machine for a turbocharger according to claim (1), wherein the plurality of equally spaced grooves are formed at an angle with respect to the cylindrical axis. (3) The ferromagnetic material is made of an amorphous ferromagnetic material formed into a foil shape.
The rotating electrical machine for a turbocharger described in item 1).