JPS5967404A - Detector of radial displacement of rotary body - Google Patents

Abstract

PURPOSE:To detect the radial displacement of a target accurately and efficiently by connecting four windings so that magnetic fluxes generated instantaneously when a current flows through the four windings flow in the same direction. CONSTITUTION:When a current is made to flow from a voltage impression terminal A2 to a terminal B2, magnetic fluxes generated in magnetic poles 201- 204 with windings flow all toward the center of a ring-shaped core. In other words, each magnetic pole has the polarity as indicated by N, and the whole magnetic fluxes flow primarily as indicated by broken lines. Even when a target 200 is displaced in the direction of an axis Y, for instance, the impedance of the magnetic poles 201 and 203 is unvaried and thus a constant voltage can be impressed between the terminals A2 and B2, whereby the sensitivity of the outputs X2 and Y2 of a detector is maintained as constant. Consequently, the radial displacement of the target 200 can be detected accurately and efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radial displacement detector for a rotating body.

The principle of a magnetic displacement detector will be described.

A magnetic circuit is constructed between a magnetic pole with winding, a magnetic pole with no winding, and a target, and the change in distance between the target and the magnetic pole with winding is treated as a change in the inductance of the winding. represent. This change in inductance is detected as an electrical change by applying an alternating current to the winding. That is, the displacement of the target is converted into a change in the inductance of the winding, and this is electrically detected.

The present invention relates to a winding connection method that accurately and efficiently converts the displacement of a target into a change in the inductance of each winding.

The method will be described below.

FIG. 1 is a diagram showing a method independent of the winding connection method according to the present invention. Now, current flows from AI to B1 f
'', winding was performed.The direction in which the magnetic flux generated by the magnetic poles 101 to 104 flows is 101 to 103idl, l
104 points toward the center of the ring-shaped core, and 104 points outward. That is, the polarity of the magnetic pole generated in each magnetic pole is N in FIG.
E! It will be shown as follows.

At this time, the overall flow of magnetic flux is mainly as shown by the broken line, and the amount flowing to the magnetic poles 105 to 112 that are not wound is small. For example, if we consider a case in which the target 100 is displaced in the Y-axis direction, the inductance of the magnets 44101 and 103 changes as the distance between the magnetic pole 104 and the target 100 changes.

Detector output X1. The sensitivity of Yl is proportional to the applied voltage between AI and B1. Since a power supply always has internal impedance, the applied voltage changes when the inductance between AI and B1 changes, and the detection sensitivity changes due to displacement components in other axial directions. Figure 2 shows how the lines are connected.

When a current flows from A2 to B2, the magnetic fluxes generated in the wound magnetic poles 201 to 204 all flow in the direction of the center of the ring-shaped core.

That is, the polarity of each magnetic pole becomes as shown by Nτ in FIG. At this time, the flow of the entire magnetic flux is mainly as shown by the broken line.

Therefore, for example, even if the target 200 is displaced in the Y-axis direction, the inductance of the magnetic poles 201 and 203 does not change, and a constant voltage can always be applied between iA2°B2, increasing the sensitivity of the detector output X2°Y2. can be kept constant. Therefore, by using the present invention, it is possible to accurately and efficiently detect the radial displacement of the target without being adversely affected by fluctuations in detection sensitivity due to other axial displacement components.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a method of connecting windings not according to the present invention, and FIG. 2 is a diagram showing a method of connecting windings according to the present invention. t OO and 200... Targets (rotating bodies) 101 to 104 and 201 to 204...
・Magnetic poles 105 to 112 and 205 to 212 with winding...
- Magnetic pole AI without winding: [31 and A2. B2... Voltage application terminal X
1 and X2......X-axis direction displacement detection terminals Y1 and Y2......Y-axis direction same detection terminals and above Applicant Daini Seidamasha Co., Ltd. Agent: Patent Attorney Mogami Written amendment of administrative procedures (spontaneous) Mr. Commissioner of the Japan Patent Office 1, Indication of the case, Patent Application No. 166271 of 1982, 2, Name of the invention: Radial displacement detector for rotating body 3, Person making the amendment: Relationship: Applicant 6-31-1-4 Kameido, Koto-ku, Tokyo, is amending Figures 1 and 2 of the agent's drawings in the attached document.

Claims (1)

[Claims] It is composed of four magnetic poles with windings located on two orthogonal axes, and at least four magnetic poles arranged symmetrically with respect to the two orthogonal axes and shaped like f''. In the core, the four windings are connected in such a way that when current is passed through the four windings fC, the direction of the magnetic flux generated at the four magnetic poles that are wound at each moment is in the same direction. A radial displacement detector for a rotating body, characterized by: