SU756294A1 - Device for measuring angular rotational speed - Google Patents

Description

The invention relates to a measuring technique and can be used to measure the angular velocity of rotation with optical contactless means.

Devices are known for measuring the parameters of rotation by contactless optical means by measuring the frequency of the pulses obtained by interrupting the light beam using a disk with radial slits rotating with a measured speed [ι].

It is also known a device of a similar purpose, containing a disk, 15 covered with a layer of electroluminophore, mounted on the object under study, an opaque screen with radial slits, parallel to the disk and deposited on a photosensitive HZ layer of a photodetector £ 2].

The disadvantages of the known devices is their complexity associated with the need to use electron-5 but counting frequency meters, as well as the impossibility of a visual reference of the values of the angular velocity.

The aim of the invention is to eliminate these disadvantages. thirty

2

This goal is achieved by the fact that the device containing the disc with the phosphor, an opaque screen with radial slots and a light source is equipped with a light source located opposite one of the slots of the disc.

- In FIG. 1 shows the device a general view; in fig. 2 - the same, side view; in fig. 3 - a device in axonometry, a general view; in fig. 4 time diagram explaining the operation of the device.

The device for measuring the angular velocity contains a disk 2 mounted on the shaft 1, the speed of which is measured, covered with a layer of phosphor 3 with a fairly short finishing time. The light source 4 is located in front of the disk 2 so that the focus of its optical system is located on the surface of the phosphor 3, and near the disk .2, parallel to the surface covered by the phosphor 3, is the screen 6 illuminated by the light source 5, in which there are "risks" of the scale angular velocity radially located slots 7, forming a ring, is756294

shedding against the phosphor-coated 3 part of the disk 2. When the light source 4 is turned on, its luminous point appears on the surface of the phosphor 3 at its focus. Due to the fact that after illumination ceases, the luminescence intensity of the phosphor decreases with * time (line 9 of the diagram), due to the rotation of disk 2, a 4 luminous phosphor band having the shape of an arc of a circular arc emerging from under the light source forms on the surface of phosphor 3. The intensity of the glow of the phosphor in this band decreases with distance from the place illuminated by the source 4.

Since the time for reducing the intensity of the luminescence of the phosphor to a predetermined level depends only on the properties of the phosphor and under the same conditions of the initial illumination. It is a constant value, the length in radians. arc, within which the intensity of the glow of the phosphor, exceeds the set level, is

H * = 2 L. p "S, 25

where "l - the time to reduce the intensity of the glow of the phosphor From the initial to the specified level in seconds, 30

η - disk rotation speed in revolutions per second.

Observing the luminous band on the surface of the phosphor 3 through the slot 3 illuminated by the source 5 of the screen 6, the operator makes a reading of the angular velocity on the scale formed by the slots 7 in the place where the decreasing brightness of the strip of the phosphor 3 (line 8 of the diagram) becomes equal to the brightness of the illuminated screen 6 (line 9 of the diagram).

For normal operation of the device, the following conditions must be met (see Fig. 2); the orbital period of the disk 2, corresponding to the highest measured speed, must be longer than the time for reducing the luminous intensity of the phosphor 3 from the initial level to the level at which the reading is made; the intensity of the lighting of the phosphor 3 source

4 and 5 screen source 5 should be the same; stray light on the screen 6 near the scale and the light of the phosphor 3 light source

5 are not allowed. In addition, the luminescence color of the phosphor 3 and the color of the light reflected by the screen 6 should be as close as possible.

Claims (1)

Claim A device for measuring the angular velocity of rotation, containing a disk covered with a phosphor layer, mounted on the object under study, an opaque screen with radial slots parallel to the disk, characterized in that, in order to simplify the design and enable visual reading of the angular velocity values, it is provided with a source light, located opposite one of the slits of the disk.