JPS6121612Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a stator of a magnetic bearing, and the ratio of the volume of the electromagnet to the volume of the stator is increased to improve the ratio of load capacity to volume of the magnetic bearing. The purpose is to provide a stator that efficiently dissipates heat.

Magnetic bearings are used in high-speed rotating machines because they control the attractive force of electromagnets to suspend and rotate a rotating body in the air, so the frictional resistance is extremely small compared to mechanical bearings. However, the ratio of the bearing's load capacity to volume is small. In other words, since bearings are becoming larger, there has been a desire for a structure that allows for smaller magnetic bearings.

FIG. 1 shows the structure of a stator of a magnetic bearing that has been proposed in the past.

In the drawing, reference numeral 1 denotes a rotating body, which is attracted by electromagnets 2 and 3 arranged in the radial and axial directions.
A displacement sensor 4 detects the position of the rotating body 1 and supplies a signal to a control device (not shown). The attractive forces of the electromagnets 2 and 3 are controlled by a control device so that the positional relationship between the displacement sensor and the rotating body is constant. 5, 6, 7, and 8 are spacers for keeping the electromagnet and the sensor at a predetermined distance.
9 is a sleeve that houses the electromagnet, sensor, and spacer, as well as covers 10 and 11 on both ends and screw 1.
Fixed at 0.

In the stator of the magnetic bearing having the above structure, the coil 13 is used to increase the load capacity while keeping the volume as it is, in other words, the diameter and length as they are.
It is effective to increase the number of turns of the coil 13 and to increase the current flowing through the coil 13. However, the current that can be passed through the coil is limited by the wire diameter of the coil, so a method of increasing the number of turns of the coil is chosen. However, this structure has the disadvantage that the number of turns of the coil 13 is limited by the inner diameter of the spacer due to the presence of the spacers 5 and 7. In addition, fins 14 are provided on the sleeve 9 to dissipate the heat generated by the electromagnet, but since the contact between the electromagnet and the sleeve is incomplete, the thermal resistance is large and the heat of the electromagnet is not efficiently transferred to the sleeve, resulting in insufficient heat dissipation. There was a drawback.

The present invention improves the above-mentioned drawbacks and provides a stator for a magnetic bearing that increases the number of turns of the electromagnet coil to improve the load capacity to volume ratio of the bearing and efficiently dissipates heat generated from the electromagnet. The purpose is to

An embodiment of the present invention will be explained based on FIGS. 3 and 4.

In the drawing, 15 is a sensor, and 16 and 17 are electromagnets that levitate the rotating body 1 in the air as in FIG. The iron cores of the electromagnet 16 and the sensor 15 are constructed by laminating thin soft magnetic materials (generally made of silicon steel plates). 18, 19, 20, and 21 are spacers. 22 is a tie rod with nuts 23 on both ends, which together with covers 24 and 25 connect an electromagnet;
Tighten and secure the sensor and spacer.

The major difference between the structure of the present invention and the conventional structure is that, as is clear from the drawings, the present invention does not use a sleeve. According to the present invention, by removing the sleeve, the radial space is increased and the number of turns of the electromagnetic coil 26 can be significantly increased compared to the conventional one, and the diameter and length of the stator of the magnetic bearing can be changed. It becomes possible to increase the ratio of the bearing's load capacity to volume without causing any problems.
In other words, if the same level of load capacity as conventional magnetic bearings is required, it is possible to design a magnetic bearing smaller than conventional magnetic bearings. In addition, since the heat of the electromagnet can be directly dissipated, heat dissipation can be carried out efficiently, and if the outer diameter of the thin soft magnetic material that makes up the iron core 16 is changed as shown in 16a and 16b and stacked, the heat dissipation fins can be This has the effect of making heat dissipation more efficient.

[Brief explanation of the drawing]

Fig. 1 is a structural cross-sectional view of a conventional magnetic bearing, Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1, Fig. 3 is a structural cross-sectional view of a magnetic bearing that is an embodiment of the present invention, and Fig. 4 is a structural cross-sectional view of a magnetic bearing according to an embodiment of the present invention. Third
It is a BB sectional view of the figure. 1... Rotating body, 2... Electromagnet, 3... Electromagnet 4
...Sensor, 5,6,7,8...Spacer,
9...Sleeve, 10, 11...Cover, 12...
...Volt, 13...Coil, 14...Radiating fin, 15...Sensor, 16, 17...Electromagnet, 1
8, 19, 20, 21... Spacer, 22...
Tie rod, 23...Nuts 24, 25...Cover, 16a, 16b...Thin soft magnetic material.

Claims (1)

[Claims for Utility Model Registration] (1) An electromagnet, a sensor, and a stator for a magnetic bearing characterized by stacking spacers in order and tightening them with tie rods in order to maintain a predetermined distance between the electromagnet and the sensor. (2) A stator for a magnetic bearing as set forth in claim 1 of the utility model registration, characterized in that a heat dissipation fin is formed by laminating thin plate iron cores of electromagnets having different outer diameters.