SU1335945A1 - Device for controlling shaft rotational speed - Google Patents

Abstract

The invention relates to the field of automatic control and can be used in the control of the frequency of rotation of the rotor of the engine. The purpose of the invention is to improve the accuracy of the device. The device comprises a shaft 1 with a cylindrical housing 2 of a nonmagnetic electrically conductive material with an insulating base fixed on it coaxially. The surface of the housing 2 is covered with dielectric 3, and its cavity is filled with an electrically conductive ferromagnetic fluid 4. A permanent magnet 5 with poles, annular with radial magnetization, one of which is made in the form of a rod 6 passing inside the cylindrical housing along its rotation axis, is fixed with a conductive ferromagnetic liquid. and the other pole, covering the cylindrical body 2, is made in the form of a glass 7 of conical shape. Electrically conductive ferromagnetic fluid 4, electrically conductive cylindrical body 2 with dielectric 3 are a capacitive liquid level sensor. 1 il. sl cobalt with 4 cl

Description

The invention relates to the automatic control and regulation of the speed of rotation of various mechanisms and may find application in the controllers of the frequency of rotation of the rotor of the engine.

The purpose of the invention is to improve the accuracy of the device.

The drawing shows a device for controlling the speed of rotation of the shaft, a slit.

1e - dielectric thickness; The first one is the speed of rotation of the shaft 1. The magnetic field created by the ring magnet 5 prevents the ferromagnetic fluid from flowing out of the housing 2 when the device changes its position in space. The magnetic force holding the fluid in proportion to the gradient of magnetic energy has a maximum value

„In the places of minimum clearances (line A) and

The device consists of the shaft 1 with the minimum fixed in the places of the maximum bore coaxially cylindrical on it (line B). With this arrangement, the poles (in the start-up 2 of a non-magnetic electrically conductive material with an insulating base. The surface of the body 2 is covered with dielectric 3, and its cavity is filled with an electrically conductive ferromagnetic liquid 4. 15 poles, one of which is made in the form of a rod 6, passing inside the cylindrical body 2 along its axis of rotation, and the other pole covering the cylindrical body 2 is made in the form of a cup 7 con Electrically conductive ferromagnetic fluid 4, an electrically conductive cylindrical body 2 with a dielectric 3 25 constitute a capacitive liquid level sensor.

The device works as follows.

When the shaft 1 rotates, the free surface of the liquid 4 takes a parabolic shape, depending on the speed of rotation. This leads to a change in the active surface area of the capacitor electrodes 2 and 4.

The electrical capacitance of the sensor is defined as 35

2 g, 2 lg g

G eeo-f ho + eeo-f - j.

where HO is the fluid height at

g is the radius of the cylindrical body 2;

8 - dielectric dielectric 3;

permeability

40

in the form of a glass of conical shape) the magnetic force has a direction from the region of the minimum floor to the region of the maximum, i.e. toward the bottom of the cylindrical body 2.

The magnetic force created by the ring magnet is

F.X- | f (-f-l) n,

 J n l-lft

where Q | i is the magnitude of the magnetic flux;

1 ,, - magnetic permeability of ferromagnetic fluid; 5c is the average area of the poles 6 and 7; and - the angle between the hull and the pole.

Claims (1)

Invention Formula A device for monitoring the speed of rotation of the shaft, comprising a cylindrical body with a ferromagnetic fluid, a permanent magnet coaxially mounted on the shaft, and a capacitive liquid level sensor, characterized in that, in order to improve the accuracy of the device, the permanent magnet is designed as fixed on the shaft coaxially with The cup is of conical shape, inside of which there is a cylindrical body, and a rod located inside the cylindrical body, with the rod being the one pole of the magnet and the cup being the other pole. the minimum in places of maximum gaps (line B). With such a performance of the pole (in 15 ,. five 0 five 0 in the form of a glass of conical shape) the magnetic force has a direction from the region of the minimum floor to the region of the maximum, i.e. toward the bottom of the cylindrical body 2. The magnetic force created by the ring magnet is F.X- | f (-f-l) n,  J n l-lft where Q | i is the magnitude of the magnetic flux; 1 ,, - magnetic permeability of ferromagnetic fluid; 5c is the average area of the poles 6 and 7; and - the angle between the hull and the pole. Invention Formula A device for monitoring the speed of rotation of the shaft, comprising a cylindrical body with a ferromagnetic fluid, a permanent magnet coaxially mounted on the shaft, and a capacitive liquid level sensor, characterized in that, in order to improve the accuracy of the device, the permanent magnet is designed as fixed on the shaft coaxially with The cup is of conical shape, inside of which there is a cylindrical body, and a rod located inside the cylindrical body, with the rod being the one pole of the magnet and the cup being the other pole.