JPS59180118A - Magnetic thrust bearing - Google Patents

Abstract

PURPOSE:To prevent damage to a rotary part by putting in the lower side a fixation part iron core of a thrust bearing joined to the stator side and putting in the upper side, in opposition to said iron core, a rotary part iron core of a magnetic thrust bearing joined to the rotor side and further providing an exciting coil on the plane of opposition of both cores. CONSTITUTION:A rotary part iron core 7 of a magnetic thrust bearing 1 joined to a rotor 3 side and a fixation part iron core 4 of a magnetic thrust bearing 1 joined to a stator 2 side are arranged in opposition to each other through a gap 8 with the rotary part iron core 7 in the upper side. Said iron core 7 and 4 are respectively provided with an exciting coil 5 and 6 same in the number of coiling. The coils are connected so as to make series with each other and also excited so as to generate magnetomotive force by means of the same current and in the direction reverse to each other. When the rotor 3 moves up and down due to change of load operating on it, change of the lifting force 10 of the magnetic thrust bearing due to change of the gap 8, corresponding to said change of load, operates to absorb a change of load.

Description

[Detailed description of the invention] [Voice 1! , f technical field] The present invention provides a method in which the rotating part is connected to the rotor side of an electric machine, and the fixed part is connected to the stator side of the electric machine, and the rotating part and the fixed part are connected through an appropriate gap. The present invention relates to a magnetic thrust (tl+) bearing for a chamber-shaft type electric machine in which the rotor is lifted up by the magnetic force acting between the shafts and the rotor when the shafts are arranged so as to face each other.

In this single magnetic thrust bearing, when the thrust load acting on the rotor increases in the same direction as the weight of the rotor, the magnetic force increases accordingly, and the rotor is immediately removed. It is hoped that this will be done in such a way that the power of

[Prior art and its problems]

In general, this type of magnetic thrust bearing reduces the static friction torque at the time of machine startup and the total loss during steady operation, resulting in smooth startup and improved operating efficiency. In addition, it is well known that the thrust bearings of LT line machines can be made smaller and their reliability can be improved.

In a conventional magnetic thrust bearing, as shown in FIG. 1, the rotating part iron core 7 of the magnetic thrust bearing 1 is located below the fixed part iron core 4 through a suitable gap 8, so that no force acts between them. The excitation coil 5 that generates magnetic force is connected to the gap 8 of the fixed part iron core 4.
When an excitation current 6 is applied to the excitation coil 5 provided only on the side -CI,), the excitation current 6 is applied to the excitation coil 5 in the direction of the 4j direction shown in the drawing, and the fixed part iron core 4. Magnetic flux 9 is generated in the direction of the arrow shown in the gap 8.1Q (around the rotating part iron core 7), and the magnetic attraction force generated between the fixed part iron core 4 and the rotating part iron core 7 causes the rotating part iron core 7 to The rotating part including the rotor 3 of the electric machine is lifted upwards toward the fixed part iron core 4. In this case, the rotating part (the lifting force 10 is equal to On the other hand, it has the characteristics as shown in Fig. 2.When the thrust load 11 increases downward using the excitation current 6 as a parameter, the gap 8 widens and the magnetic attraction force and therefore the lifting force 10 decreases. On the other hand, when the thrust charge acts upward, the gap 8 is shortened and the suction force and thus the lifting force 10 increases. A considerable portion of the total weight of the rotating parts of the machine is charged to the generator 2, including the water wheel, by magnetic thrust) 4M + bearing 1 carries the load, and the remaining surroundings are carried by the Nζ last bearing (not shown). By adjusting the excitation current 6 of 1, stable operation can be expected as long as a significant reverse thrust force is not induced in the rotating part of the generator.However, for some reason, 'A t
48 Rotating part ζ When a large reverse thrust acts on the rotating part, the rotating part is lifted upward, but the lifting force 10 acting between the fixed part iron core 4 and the rotating part iron core 7 of the magnetic thrust/IQII receiver 1 is as shown in Fig. 2. As shown in 4-Do < , since it has the characteristic that it increases as the gear tube 8 becomes shorter,
Eventually, the rotating part of the generator will float up, and an excessive load will be applied to the reverse thrust bearing (not shown) installed in the generator, creating the risk of damaging it. However, the configuration of conventional magnetic thrust bearings can only prevent this from occurring.

[Purpose of the invention]

In view of the above-mentioned drawbacks of conventional magnetic thrust bearings, the present invention has been developed to prevent magnetic thrust bearings from occurring when a significant reverse thrust force is applied to the rotating part of an electric machine. The purpose of the present invention is to provide a simple magnetic thrust bearing that can maintain stable electric machine operation by absorbing the reverse thrust force caused by the lifting force generated between the light beams. 4-ru.

[Intersection of inventions]

In order to achieve the above object, the present invention provides the above-mentioned magnetic thrust illumination bearing, in which the fixed part iron core of the thrust bearing coupled to the stator side of the electric machine is placed on the lower side. By arranging the rotating part iron cores of the magnetic thrust bearings coupled to the child side to face each other with a suitable gap above, and providing excitation coils with the same number of turns on the opposing surfaces of both, k, respectively. Is the magnetomotive force generated by the excitation coil phase? By excitation in series in opposite directions ζ, the parts of the magnetic thrust bearing that face each other across the gap between the fixed part iron core and the rotating part iron core are magnetically A repulsive force is generated, and the repulsive force ζ is used to lift the rotating part of the electric machine.

[Practice of the Invention]>1) In Figure 3, the rotating part iron core 7 of the magnetic thrust ΦIt receiver connected to the rotor 3 side of the electric machine is connected to the fixed -'r-2 side of the electric machine. ta (niwaki surasu) 'il
The fixed part iron core 4 of the l receiver 1 is arranged to face the fixed part iron core 4 with the rotating part iron core 7 on the upper side with a gear up 8 interposed therebetween. Rotating part iron core 7
The fixed part iron cores 4 and ζ are provided with excitation coils 12 and 13 having the same number of turns, respectively, and a brush provided on the stator 2 side of the electric machine and a slip ring provided on the rotating r-3 side (both shown in FIG. The coils 1 are connected in series with each other through the coils 1 and 2, and are excited with the same current so as to generate magnetomotive forces in mutually opposite directions. As a result, the parts of the rotating part iron core 7 and the fixed part iron core 4 of the magnetic thrust bearing 1 that face each other through the gap 8 have the same magnetic polarity, and the polarity between the fixed part iron core 4 and the rotating part iron core 7 becomes the same. A mutual repulsive force acts. As a result, a lifting force 1o is generated against the rotor 31 of the electric machine via the rotating part iron core 7, and the rotating and paper parts of the electric machine are lifted up. In this case, the characteristics of the lifting force 10 and the length ζ of the gap 8 are as compared to the conventional i
As in the case of bearings, as shown in FIG. , the downward load 1] is large. When the rotor 3 descends and the length of the gap 8 is shortened, the rotating part iron cores 7 and II, 1
The repulsive force between the stator core 4 and the resulting force 1
0 increases and vice versa? A reverse thrust force in the L direction acts on the rotor 3, and when the rotor 3 rises, the gear lug 8 expands and the rotating part iron core 7
The repulsive force between the fixed part iron core 4 and the lifting force is reduced. In other words, in this case, the change in the load acting on the rotation stop 31 (when the rotor 3 is lowered by one step, the change in the gap 8) is 1. This change acts to absorb the fluctuations in the cargo position.For some reason, the reverse thrust force acts on the rotating part of the machine and the rotating part is about to float. t,), the fin thrust thrust bearing 1 cap 8 increases, and the lifting force 10 on the rotating parts decreases, and the sum of the total weight of the rotating parts of the electric machine and the lifting force becomes balanced again with the above-mentioned thrust force. Since it is stable, there is no risk that the rotating part will rise significantly and an excessive load will be applied to the reverse thrust bearing (not shown), which could easily cause damage, as in the case of conventional magnetic thrust bearings. 〕 The present invention is based on the above-described one opening < whose rotating part is r1''C.
The fixed part on the rotating side of the electric machine is the stator of the electric machine (
1], the rotating part and the fixed part are distributed so as to face each other through an appropriate gap, and the magnetic force acting between them acts to lift the rotor up by one. In a magnetic thrust bearing for a vertical electric machine, the fixing part of the electric machine is connected to the fixed part iron core of the thrust bearing on the lower side, and the fixed part iron core of the thrust bearing is connected to the lower side of the fixed part of the thrust bearing, and Magnetic thrust bearing times 1
The transmission iron cores are placed on the upper side facing each other with an appropriate gap in between, and excitation coils with the same number of turns are provided on the opposing surfaces of both, and each excitation coil is
In such a way that the magnetomotive forces in mutually opposite directions ζ are excited by the series O (by rubbing ζ), the parts of the magnetic thrust 1411 receiver that face each other across the gap between the fixed part iron core and the rotating part iron core are magnetized. The repulsive force generated by the polarity of the air lifts the rotating part of the electrical machine -70
If the rotating part ζ acts on the rotating part and changes in response to the fluctuation of the thrust force, the lifting force absorbs the fluctuation, so the rotating part ζ has a significant reverse thrust force. Even if 7 is applied, the total weight of the rotating part and the lifting force are stable in balance with the reverse thrust force described in ij, and the rotating part is unduly lifted and an excessive load is placed on the reverse thrust bearing. It has the effect of preventing damage caused by building.

[Brief explanation of drawings]

,'I'', Figure 1 is a schematic diagram showing the configuration of a conventional magnetic thrust bearing, Figure 2 is a characteristic diagram showing the relationship between the tension force and the gap in a magnetic thrust bearing (Fig. 31).
The figures each represent a schematic diagram showing the configuration of the magnetic thrust bearing of the present invention. ] Magnetic thrust! Bearing, 2. −＠Ki Machine Stator (i
iii, 3 Quasi-air machine 'D rotor side, 4. Fixed part iron core,
7 Rotating part iron core, 8 Gap, 10... Lifting JJ
, 12 Rotating part iron core excitation coil, 13 Fixed part iron core excitation coil.

Claims (1)

[Claims] ]) The rotating part is connected to the rotor side of the electric machine, and the fixed part is connected to the stator side of the electric machine, such that the rotating part and the fixed part face each other with an appropriate gap between them. In a magnetic thrust bearing of a chamber-shaft electric machine, which acts to lift up a rotor by magnetic force, the fixed part of the thrust bearing is connected to the stator side of the electric machine. The rotating part iron core of the magnetic thrust bearing, which is connected to the rotating F side of the electric machine, is placed opposite to each other with an appropriate gap between the iron core on the lower side and the rotating part iron core of the magnetic thrust bearing connected to the rotation F side of the electric machine. A magnetic thrust bearing is provided with excitation coils and is configured to be excited in series so that the magnetomotive forces generated by the respective excitation coils are in opposite directions.