JPS58147609A - Rotor magnetic circuit of device for measuring relative displacement angle - Google Patents

Abstract

PURPOSE:To enhance the resolution of the displacement angle, by attaching annular rotor yokes to a pair of rotary disks corresponding to the inner surface of the opening end of a U shaped annular fixed yoke, respectively, thereby increasing the amount of variation in inductive reactance. CONSTITUTION:The nonmagnetic rotary shaft disks 3 and 4 are fixed to coaxial shafts comprising a rotary shaft (a) 1 and a rotary shaft (b) 2, respectively. The (a) and (b) annular rotor yokes 5 and 6 are attached to the disks 3 and 4, and pole pieces (a, b) 7 and 8 are radially attached. The U shaped fixed annular yoke is constituted by annular stator yokes 9 and 10 surrounding a rotor exciting coil 12 and a tubular yoke 11. The opening side of the inner surface of the U shaped yoke corresponds to the annular rotor yokes (a, b) 5 and 6 through a gap. When the pole pieces (a, b) 7 and 8 face squarely to each other, magnetic circuit resistance becomes the minimum value, the inductive reactance becomes the maximum value, and the exciting current of the fixed exciting coil 12 becomes minimum.

Description

Detailed Description of the Invention The present invention relates to a rotating relative displacement angle measuring device that measures the inductive reactance that changes in response to the relative displacement angle between a pair of rotating discs using the excitation current of a fixed annular excitation coil. Marriage related to child's magnetic circuit.

Measurement of the relative displacement angle between concentric disks in a rotating wAK is used for torsion-axis power needles and the like.

Since the twist angle of the rotating shaft is proportional to the rotational torque, the shaft power can be measured from the product of the rotational speed 2 at that time. To measure such twist angles, there is a variable inductive reactance type relative displacement angle measuring device that can measure the rotating shaft without contact.
This is done by arranging induction cores radially in a T-disk mounted on a rotating shaft and another disk that can rotate about the shaft and facing each other. The outer station is surrounded by a U-shaped fixed annular yoke, and an annular fixed excitation wire ring is provided, and the relative displacement angle between the rotating disks is determined from this excitation current. .

In this case, in order to increase the output from the annular fixed excitation wire ring with respect to the relative displacement angle, or to improve the resolution of the displacement angle, the companion K is inserted into the co-located fixed annular yoke that surrounds the annular fixed excitation wire ring. It is necessary to reduce the magnetic resistance that occurs in the gap between the circumferential open end and the outer periphery of the AM piece of the induction core arranged radially, and to increase the difference between the maximum and minimum values of inductive reactance, that is, the variable amount. It is.

Conventionally, a plurality of magnetic pole pieces of the cast iron core are arranged radially on the surface of a non-magnetic rotating disk at the open end of a dust ring fixed yoke, but the magnetic pole pieces of the cast iron core are arranged radially on the surface of a non-magnetic rotating disk. A magnetic space is formed between them, and the total effective length of the magnetic pole piece is V2 compared to the inner circumference of the open end of the U-shaped annular fixed yoke.
The utilization rate of the magnetic flux from the inner circumference of the open end is as follows:
It ends up being even smaller than this.

The present invention has been made in view of the above points, and rotor annular yokes are respectively attached to 91 pairs of rotating disks corresponding to the inner periphery of the open end of the U-shaped solid fixed yoke. The magnetic flux from the inner periphery of the open end of the U-shaped fixed yoke passes through the air gap and reaches the rotor annular yoke, and the magnetic flux is narrowed by nine magnetic pole pieces arranged on the surface of the yoke and transmitted. Therefore, it is possible to increase the utilization rate of the total magnetic flux generated by the fixed excitation wire ring corresponding to the relative displacement angle, increase the amount of change in inductive reactance, and increase the resolution of displacement angle. .

This will be explained with reference to the diagram. FIG. 1 is a sectional view of the relative displacement angle measuring device of the present application, in which (1) is an 8-rotation axis, and (2) is a 5-rotation axis, which are coaxial with the former (1). (8), (4) are respectively (al, (b1 non-magnetic rotating shaft disk fixed to the rotating shaft, (5), (6) are on the rotating shaft disk (8), (4)
a, b rotor annular yokes, (71,
(8) is the magnetic pole pieces a and b attached radially on the annular yoke (5) and (6); (9) and +10 are the stator annular yoke surrounding the fixed excitation wire ring 02; I is the annular yoke; It is a cylindrical yoke, and the annular yoke (9) and ha constitute a U-shaped fixed lug-like yoke, and the open end of the inner circumference passes through the gap (at, (b1) rotor-shaped yoke. These correspond to irons (5) and (6). Figure 2 ■) is a side view of the magnetic circuit, and (B) is its front view. In Figure 2 ■), the fixed excitation wire ring (I ring) is The magnetic circuit generated by the excitation of the excitation current is a rotor-shaped yoke (51-a
Magnetic pole piece (7) - air gap - b magnetic pole piece (81 - b rotor annular yoke (6) - air gap - b fixed annular yoke (1□ - cylindrical yoke 01
1-4 fixed annular yoke (91-gap), forming a circular magnetic circuit shown by the arrow.

In FIG. 2B, the magnetic flux φ reaches the magnetic pole piece (7) K through the inner circumferential open end machining gap of the fixed annular yoke (9). , or there is a magnetic flux φ that reaches the magnetic pole piece (7) K from an oblique direction, but there is also a magnetic flux φ that passes through the rotor m-shaped yoke (5) and reaches the magnetic pole piece (71), and this magnetic flux φ, is useful for improving the efficiency of magnetic flux utilization.When the magnetic pole pieces a and b (7) and (8) face forward, the magnetic circuit resistance becomes the minimum, the inductive reactance becomes the maximum, and the fixed excitation line Ring (12 excitation electric I
! i! is the minimum. Next, at a displacement angle in which the radially arranged magnetic pole pieces (7) and (8) do not face each other at all and are out of alignment, the excitation current becomes maximum as described above. According to the present invention, the change in excitation current with respect to the relative displacement angle is increased compared to the conventional case without the rotor annular yoke, and the resolution of the displacement angle can be significantly improved.

The rotor annular yoke (5) in the figure is made by cutting electric iron plates into an annular shape and stacking them, and the magnetic pole pieces (7) are made by laminating the sides of the iron plates. Since the layers are carefully stacked in parallel to each other as shown in the figure, the magnetic flux is transmitted along the surface of the iron plate, making it possible to measure the reduction in the magnetic resistance of the pole piece. FIG. 8B shows an example in which the magnetic pole pieces (7) and (8) are made of a material such as ferrite, which is extremely effective in reducing the magnetic resistance in the magnetic pole piece (7). Fig. 8C is a side view of the rotor, in which the rotor annular core (5) and the magnetic pole piece (7) are integrated to form a rotor magnetic circuit. The electrical iron plates are bent into an L shape as shown in the figure, stacked, and glued together with resin etc. The parts that are placed back to back are called magnetic pole pieces (7+), and both legs are used as the rotor ring yoke (
5) Food should be prepared as follows. U-shaped fixed annular core +
91. (The magnetic flux of 10 passes through the air gap to the rotor annular yoke (
From the cut direction of the magnetic pole piece (7), pass through the gap from the cut of the magnetic pole piece (7) along the surface of the iron plate of the magnetic pole piece (7), and insert the opposite magnetic pole piece (6).
) is formed. As mentioned above, the magnetic circuit has no part that passes through the normal direction of the electric iron plate, and is designed to reduce magnetic resistance.

As described above, the present invention uses a rotor ring-shaped yoke corresponding to the open end of the inner periphery of the square-shaped yoke, and arranges covered magnetic pole pieces radially on the rotor to form a rotor magnetic circuit. Therefore, the magnetic flux from the U-shaped annular yoke can be used extremely effectively, the output of the relative displacement angle measuring device can be increased, and the resolution of the displacement angle can be greatly increased. .

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the relative displacement angle measuring device, Fig. 2 is an explanatory view of the magnetic circuit, A is a side view II, B is a front view, and Fig. 8 is an explanatory view of the rotor part, A is an explanatory view of the rotor annular joint. If this is an electric iron plate made of iron and magnetic pole pieces, B is a magnetic pole piece made of something like ferrite, and 0 is an electric iron plate bent into an L shape and laminated to integrate the magnetic pole piece and rotor annular yoke. For the rotor, configure the following. 1.2: a and 5 rotating shafts, 8.4: rotating shaft disk, 5.
6: a and 5 rotor annular yokes, 7.8: a and b pole pieces, 9, lo: a and b stator annular yokes, 11: tubular yoke, 12: fixed excitation wire ring.

Claims (1)

[Claims] The magnetic pole pieces of the induction iron core of a pair of rotating shaft disks of concentric shafts are arranged radially and faced each other, and the outer periphery of the magnetic pole pieces is surrounded by an annular fixed excitation wire ring surrounded by a yoke. In a device for measuring a relative displacement angle in a rotating state using an excitation current, rotor annular yoke pipes are attached to the two pairs of rotating shaft decks corresponding to the open ends of the inner circumference of the U-shaped fixed bulk yoke, and A rotor magnetic circuit for a relative displacement angle measuring device, characterized in that a plurality of magnetic pole pieces are arranged radially on the yoke.