SU937027A1 - Apparatus for monitoring centrifugal machine vibration - Google Patents

Description

(54) DEVICE FOR VIBRATION CONTROL CENTRIFUGES

one

The invention relates to centrifugal devices, in particular, devices for automatically controlling the operation of a centrifuge, and can be used in devices having structural elements that are balanced and rotating with high frequency.

When the centrifuge operates with an increase in the rotor speed, the magnitude of the vibration accelerations increases dramatically.

An excess of the acceleration value of the allowable value or for a given rotor speed indicates a rotor imbalance or a fault in the drive system. This can lead to a breakdown of the centrifuge. To prevent emergency situations, it is necessary to control the magnitude of the vibration accelerations of the centrifuge or its individual parts.

A device for controlling vibration of a centrifuge is known, comprising a sensor for vibration acceleration of a centrifuge housing connected to an actuator via an amplifier and a threshold element connected in series, and connected to the last setting device 1.

However, the known device has insufficient accuracy in controlling the vibration of centrifuges due to the presence of a constantly predetermined level of operation of the threshold element when the magnitude of the vibration accelerations is non-linear to the rotation frequency of the centrifuge rotor.

The aim of the invention is to improve the accuracy of the centrifuge vibration control over the entire frequency range of the rotor rotation.

This goal is achieved by the fact that a device for controlling centrifuge vibration, containing a vibration acceleration sensor of a centrifuge body, connected to an actuator through an amplifier and a threshold element connected in series, and connected to the last unit, is additionally equipped with a rotor speed sensor, frequency-voltage converter and corrector, with echo 20. The frequency converter is a voltage connected to the rotor speed sensor, the output is connected to a setting device and a corrector, and the output of the latter is connected to a setting device.

FIG. 1 is a functional block diagram of the device; in fig. 2 is a graph of the frequency response of the frequency to voltage converter; in fig. 3 - the same, the output voltage of the corrector; in fig. 4 is a graph of the magnitude of the vibration accelerations of the centrifuge body versus the rotor speed (curve a) and the setpoint output signal — a predetermined trigger level of the threshold element (curve b).

The device for controlling the centrifuge vibration contains a sensor, 1 vibration acceleration of the centrifuge housing, amplifier 2, threshold element 3, setpoint 4, actuator 5, rotor speed sensor 6, frequency-voltage converter 7, equalizer 8.

The device works as follows.

The signal from the vibration acceleration sensor 1 of the centrifuge housing, proportional to the vibration acceleration value of the housing, enters the input of the amplifier 2, which amplifies the input signal and integrates the high-frequency components with a certain constant integration.

The output signal of the amplifier 2 is fed to one input of the threshold element 3, to the other input of which the output signal of the setpoint adjuster 4 is received.

The output signal of the setting device 4 has a non-linear frequency response, which improves the control accuracy over the entire rotational frequency range of the centrifuge rotor. To form the necessary nonlinear characteristics of the setting device 4, the rotor speed sensor 6 is used, the frequency converter 7 is voltage 7 and the equalizer 8.

A frequency signal is fed to the input of the frequency converter 7 - a pulse signal is received from the rotor speed sensor 6. From the output of the frequency converter 7, the voltage is a constant voltage, the value of which is proportional to the rotor frequency of the rotor, is fed to the input of the setpoint 4 and the equalizer 8.

The corrector 8 is designed to create a rise in the frequency response of the reference at the resonant frequency of rotation of the rotor. The signal at the output of the equalizer 8, and consequently, at the input of the setting device 4, appears only when a voltage corresponding to the input band corresponds to a frequency band close to the resonant frequency of rotation of the centrifuge rotor.

As a result, the two input signals influence the setting device, the latter generates the output signal of the response level of the threshold element 3, which increases with increasing rotation frequency of the centrifuge rotor and has the necessary rise in the frequency band close to the resonant one.

When the vibration accelerations exceed the permissible level for each rotor speed, a threshold element is triggered and at its output a signal appears that goes to the actuating element 5. The executive element 5 converts the centrifuge drive to the "Braking" mode and turns on the emergency light and sound signaling.

The proposed device allows to increase the accuracy of centrifugal vibration control. fugues in the entire frequency range of the rotor rotation by creating a nonlinear frequency response of the response level

threshold element.

Compared to the centrifuge TsL-4000 used, which does not have a device for controlling vibrations, the centrifuge containing the proposed device has the ability to control the health of the centrifuge drive due to the presence of a device that controls the magnitude of vibration accelerations in the entire rotor rotational frequency range. This reduces the cost of maintenance work (by increasing the reliability of the centrifuge) and increases the productivity of the centrifuge.

Claims (1)

Invention Formula 5 A device for controlling centrifuge vibration, containing a vibration acceleration sensor of a centrifuge body, connected to an actuator through a series-connected amplifier and threshold element, and connected to the last setter, characterized in that it is additionally equipped with a rotor speed sensor, a converter the frequency is voltage and the offset, while the frequency converter input is voltage is connected to the rotor speed sensor, the output is to the setpoint and offset, Output poslednegopodklyuchen to dial. Sources of information taken into account during the examination 1. Patent of the GDR No. 108467, cl. B 04 B 7/06, 1973 (prototype). them (oSJMUH) Fi.