CN1105160A - Rotor slip ring assembly for homopolar generator - Google Patents

Abstract

The present invention relates to an improved rotor slip ring design for a homopolar generator that combines the concepts of channeling magnetic flux and channeling electrical circuitry to separate the magnetic flux from the electrical circuitry, thereby reducing back emf. The separation of the magnetic field lines from the circuit is achieved based on the principle that current flows through the path of least resistance and the magnetic field crosses the magnetic circuit of least reluctance.

Description

The present invention relates to unipolar generators, and more particularly, the invention relates to the design and construction of rotor slip ring assemblies for drum-type unipolar generators.

Unipolar generators, also known as acyclic or single-field generators, are characterized by containing a disc-shaped or cylindrical conductive armature arranged to rotate about a central axis relative to a magnetic field, ( In the above-mentioned magnetic field, the magnetic field lines pass through the armature surface in a direction parallel to the axis of rotation), thereby generating a continuous current.

In a conventional unipolar disk generator, an electrically conductive disk rotates about its central axis, while a magnetic field is arranged to extend parallel to the disk axis through opposing faces of the disk. A pair of brushes are respectively positioned to engage the central and peripheral surfaces of the disc to provide an electrical connection to the external load.

In drum-type unipolar generators, the rotor may consist of a cylindrical housing of conductive material such as copper that operates like a slip ring, hot pressed or pressed to a ferromagnetic material. and directly to the solid inner cylindrical core of the drive shaft or input shaft. The magnetic field excitation system includes two DC electromagnetic field coils or superconducting magnetic field coils placed at the two axial ends of the rotor in a fixed position. The magnetic field excitation system needs to be charged to generate the same magnetic field polarity that can pass through the two axial end faces of the solid rotor core.

In the case of permanent magnets as the source of the magnetic field, the rotor core consists of a piece of ferromagnetic material at the center in contact with two pieces of permanent magnets, each facing a piece of ferromagnetic material at the center With the same magnetic field polarity, the permanent magnet pieces may also be connected to additional pieces of ferromagnetic material forming the opposite axial ends of the laminated rotor core, serving as all the laminations of the cylindrical rotor core of the main rotor body. The blades are directly connected to a drive shaft or input shaft. An external power source is connected to the drive shaft of the rotor to cause the rotor to rotate about the pivot axis, thereby producing a DC output voltage along the axial length of the rotor.

In these motors, a set of current collectors is installed at each axial end of the rotor passing full load current. The brush is located at the contact position between the axial end of the rotor and the rotor shell. The above shell is used as a slip ring and passed through a set of The brush transmits an electromotive force to the external circuit, and then feeds back to the rotor shell through another set of brushes. When the current is transmitted to the load, the interaction between the current flow path and the magnetic flux path passing through the center of the rotor shell along the circumference of the rotor will generate a force that decelerates the rotor. The deceleration force of the rotor is due to the interaction between the conductor field and the generator. resulting from the typical motor response in a generator due to the main field interaction.

The present invention provides an improved rotor slip ring assembly for a single-stage generator. The present invention combines the concepts of splitting the flux lines and splitting the current flow path to separate the flux lines from the current flow path to reduce back electromotive force. The above-mentioned separation can be achieved according to the principle that the current flows through the circuit of the least resistance and the magnetic field passes through the magnetic circuit of the least reluctance.

It is therefore an object of the present invention to provide a unipolar generator with greater operating efficiency.

It is a further object of the present invention to provide an improved rotor slip ring design for homopolar generators.

Another object of the present invention is to provide a separate flux path for the rotor case slip ring assembly, separate from the current path.

From the preferred embodiment of the present invention described below in conjunction with accompanying drawing, other purpose and advantage of the present invention will be understood better, in the accompanying drawing:

1 is a side view of a partial section of a unipolar motor manufactured according to an embodiment of the present invention;

Figure 2 is a side view of a laminated inner rotor assembly manufactured according to a preferred embodiment of the present invention;

Figure 3 is a side view of a solid inner rotor assembly and field excitation system;

Figure 4 is a perspective view of a laminated inner rotor and a sliding assembly with current collectors according to the prior art;

Figure 5 is a perspective view of a laminated inner rotor and a slip ring assembly with collectors according to a preferred embodiment of the present invention;

Figure 6 is a side view, partially in section, of the slip ring rotor housing of the preferred embodiment.

Referring to Fig. 1, the drum-type monopolar generator of the present invention mainly comprises a cylindrical rotor 10 with an input shaft 12 adapted to be connected to a prime mover (not shown), the input shaft 12 having a central axis passing through bearings 16 and 18 Installed in the stator member 20 to rotate, the stator member 20 is provided with a space 22 in which several brush assemblies 24 and 26 are placed, and a tension spring 28 is provided to force the brush assemblies 24 and 26 to be in contact with the housing or outer casing 14 of the rotor 10 touch.

The casing 14 of the rotor 10 used as a slip ring is made of a material such as copper with good electrical conductivity. The casing 14 has a hole 15 on the circumference of the casing 14 at the midpoint of the axial length of the rotor 10. The hole can be circular. Evenly spaced and aligned with each other, the holes 15 are filled with a sheet of ferromagnetic material 30 which extends through the thickness of the housing 14 of the rotor 10 . The rotor core 41 (see Figure 2) of the rotor 10 is installed inside the housing 14, and the two permanent magnets 44, 46 (see Figure 2) located in the rotor core (41) provide a magnetic field, which passes through the ferromagnetic material sheet 30 encounters less reluctance than through housing 14, so the magnetic field is diverged or laned and passes through the thickness of sheet 30 of ferromagnetic material and returns in the direction of flux lines 47 shown in FIG. The rotation of the rotor 10 causes an electromotive force generated along the axial direction of the rotor housing 14. When sliding electrical contact occurs between the rotor 10 housing 14 and the brushes 24, 26, the current indicated by the arrow 36 moves along the axial direction of the rotor housing 14. flow, and split or bifurcate between the ferromagnetic material sheets 30 to flow to the brush assembly 26 and flow out to an external circuit (not shown) through the wire 38, and the current returning from the external circuit passes through the brush through the wire 40 Assembly 24 returns to rotor 10 .

Referring to Fig. 2, the inner cylindrical rotor core 40 comprises a plurality of pieces, wherein two pieces 44, 46 are made of permanent magnets and are separated by a piece of ferromagnetic material 42, which is located in the inner rotor core. Near the midpoint of the axial length of the assembly 41, the permanent magnet pieces 44 and 46 are axially aligned such that the same magnetic poles are in contact with the ferromagnetic material piece 42, and the magnetic field lines 47 converge near the midpoint of the axial length of the ferromagnetic material piece 42 , and flow out of the peripheral surface 43 and flow along the route shown by the dotted line of the reference number 47 . The inner rotor core 41 may have pieces 48 and 50 disposed at each axial end of the rotor core assembly 41 in contact with or adjacent to the permanent magnet pieces 44 and 46 . The input shaft 12 passes axially through the center of the inner rotor laminations 42, 44, 46, 48 and 50 and is fastened thereto in a suitable manner.

Referring to FIG. 3, there is shown another alternative preferred example structure of a magnetic field excitation system and an inner rotor core 54, wherein the inner rotor core 54 is made of integral ferromagnetic material and is not at the axial end 51, 53 fixed in a rest position of the stator member (not shown), but not in contact with the rotor core 54, the induction windings 56 and 58 are energized to create two shafts passing through the solid rotor core 54 The polarity of the magnetic field facing the end faces of ends 51 and 53 is the same (upward direction is shown in the figure), as shown by the dotted line 59 in the figure. An input shaft 60 is provided and fastened to the solid rotor core 54 in a suitable manner.

Referring to Figure 4, there is shown a complete rotor assembly 61 which is in common with the prior art in that a cylindrical housing 62 made of a non-ferromagnetic material of good electrical conductivity such as copper is pressed or hot pressed into it On the rotor core 64, the thermal press fit of the cylindrical shell 62 on the inner rotor core 64 is carried out in this way, that is, by heating the cylindrical shell 62 and quenching the inner rotor core 64, and then pressing the shell 62 on the inner rotor core 64, and then simultaneously cool them to room temperature. The magnetic circuit 65 generated in the inner rotor core 64 converges within the midpoint of the axial length of the rotor 61 and passes through the cylindrical housing 62, thereby generating a uniform penetrating magnetic flux 66 through the cylindrical housing 62 (inside the dotted line surface) of the annular surface. The magnetic circuit 65 shown in Fig. 4 shows only one flux plane, in fact, the magnetic circuit 65 is in all planes including the central axis of the rotor. When the transmission force is transmitted to the input shaft 68, the two axial ends of the cylindrical housing 62 generate opposite charges and are collected by the current collectors 70 and 62. When the current is drawn from the external circuit (not shown), the current flow path 74 passes through the magnetic flux passage surface 66 on the cylindrical case 62, thereby generating a reaction force (back electromotive force) that decelerates the rotor 61.

Referring to Fig. 5, there is shown a rotor housing assembly of another alternative preferred embodiment of the present invention, wherein there is a cylindrical housing 76 made of a non-ferromagnetic material having good electrical conductivity, such as copper, the The cylindrical housing 76 has openings 77 distributed along the circumference of the housing at the midpoint of the axial length of the housing 76, the openings 77 being circular and mutually aligned and equidistantly spaced. A sheet 78 of ferromagnetic material is received within the aperture 77 and extends through the thickness of the housing 76 . The cylindrical housing 76 is fastened to the inner rotor core 80 by shrink fitting as described in the prior art with reference to FIG. The magnetic circuit referenced 81 of the rotor core 80 will branch or diverge and flow through and across the sheet of ferromagnetic material 78 and return to both axial ends 83 , 85 of the rotor 74 . When the transmission force is transmitted to the input shaft 82, opposite electric charges are generated at the two axial ends 83, 85 of the cylindrical housing 76, and are collected by current collectors 84 and 86. When the current is drawn out by an external circuit (not shown) , the current will branch or lead to or flow along the flow path referenced 88 between the sheets 78 of ferromagnetic material, which flow path is isolated and/or separated from the sheets 78 of ferromagnetic material. Because the design of the rotor housing 76 lanes and separates (or/or isolates) the magnetic circuit 81 and the electrical circuit 88, the forces that would decelerate the rotor due to the intersecting magnetic and electrical circuits in prior art designs are avoided, Thereby greatly improving the overall efficiency of the generator.

With reference to Fig. 6, this figure shows a preferred embodiment of the present invention, wherein, be equivalent to the identical parts among Fig. 5 and all use identical reference numeral to add a mantissa a and represent. The rotor core housing 76a is formed by conventional casting methods suitable for conductive materials such as copper. The casting of the rotor core housing 76a is provided with an opening or cavity 77a around the midpoint of its axial length through which the The thickness of the rotor housing 76a is such that a space can be pressed or fitted into the cavity 77a for a sheet of ferromagnetic material 78a. The ferromagnetic material sheet 78a may be made of iron or steel or an alloy containing ferromagnetic material in combination with other materials and/or a material having low magnetic resistance properties. The shape of the opening 77a and the ferromagnetic material sheet 78a is designed to maximize the conduction of the magnetic field lines through the ferromagnetic material sheet 78a. Although the piece of ferromagnetic material 78a is not limited to a specific geometric shape, it should be understood that the shape of the piece of ferromagnetic material 78a can determine the method of inserting and fastening it into the cavity 77a on the rotor core housing 76a, for all For the illustrated embodiment, the sheet of ferromagnetic material 78a is inserted into the cavity 77a from the inside. There are now many ways to fasten the sheet of ferromagnetic material 78a into the cavity 77a.

It will be obvious to those skilled in the art that various changes can be made in the present invention without departing from the spirit and scope of the invention, and that various alloys can be used, preferably alloys with low magnetic resistance.

Claims (9)

1, a kind of have a homopolar generator that comprises the rotor core of the device that produces magnetic field, and above-mentioned rotor core is enclosed within the improved slip ring, and above-mentioned improved slip ring and some contacts have and electrically contact, and above-mentioned improved slip ring contains:

One rotor core housing has some perforates around rotor core in magnetic field device passes the zone of above-mentioned housing; With

Some sheet spares that are contained in the above-mentioned perforate, the magnetic resistance value of the above-mentioned housing of magnetic resistance value ratio of this sheet spare is low.

2, homopolar generator according to claim 1 is characterized in that above-mentioned part includes a kind of ferromagnetic material.

3, homopolar generator according to claim 1 is characterized in that plurality of opening is evenly spaced apart around the central authorities of the axial length of above-mentioned housing.

4, homopolar generator according to claim 1 is characterized in that above-mentioned perforate penetrates above-mentioned housing.

5, a kind of method that is used for improving the homopolar generator gross efficiency may further comprise the steps:

Will be by being enclosed within the electric current shunting of the housing on the homopolar generator rotor core;

In the step of above-mentioned shunting electric current, the shunting, magnetic field of the rotor core generation of housing will be passed; With

The current separation in the magnetic field in shunting and shunting is opened, thereby improved the gross efficiency of homopolar generator.

6, a kind of method that is used for improving the homopolar generator gross efficiency comprises:

Make one to have two kinds of rotor core rotations that the device in the magnetic field of passing the axial length central authorities that are enclosed within the rotor core housing is provided;

By the device that comprises the material piece part that some magneto resistive ratio housings are low housing axial length central authorities around with the magnetic field bifurcated;

To flow through the electric current bifurcated of housing by the low housing of above-mentioned part of resistance ratio;

Electric current that flows through housing and the magnetic field of passing housing are kept apart, to reduce back electromotive force.

7, a kind of homopolar generator, contain:

One has two rotor cores that are used for producing the device in magnetic field, and described device is installed on the above-mentioned rotor core;

One passes the power shaft that rotor core makes it to rotate;

One is enclosed within the housing on the rotor core;

One first element that electrically contacts with housing one end and second element that electrically contacts with the housing other end; Thereby make electric current flow through first element, pass housing, flow to second element and flow back into external circuit again from an external circuit;

Have several around housing axial length central authorities and penetrate the housing of the perforate of housing;

Several its magnetic resistance values are less than housing magnetic resistance value and the sheet spare of its resistance value greater than the housing resistance value, make the magnetic flux that provides by magnetic field device can be by above-mentioned part shunting and keep apart with housing, and make the electric current that flows through housing can be between above-mentioned part shunting and separate with above-mentioned part.

8, homopolar generator according to claim 7 is characterized in that above-mentioned part contains ferromagnetic material.

9, homopolar generator according to claim 7 is characterized in that above-mentioned perforate separates equably.

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