Speed-Torque Characteristics of Torque Motor with Tape Winding Stator

The speed-torque characteristics of a torque motor with a new type of active element – the tape winding is considered. The analytical studies of the motor speed-torque characteristics determination is difficult because it is required to take into account the distributed current flowing through the winding elements. This leads to the numerical methods application, in particular, COMSOL Multiphysics software based on the finite element method (FEM). Attention is paid to the changing of the motor developed torque in the presence of EMF created in the winding during the rotor rotation. It is shown that the motor torque with a rotor rotation frequency changing depends mainly on the nature of the distributed current lines flowing through the winding elements, despite the fact that the consumed current value changes to a lesser extent. The obtained speed-torque characteristics of the torque motor has a form similar to ones of separately excited DC motors. The research results allow assessing the expected characteristics of the motor model and are an integral part of the developed design policy of the torque motor with the tape winding stator.

JUSTIFICATION OF ROTOR SPEED OF RADIAL HONEY SEPARATOR WITH THE HORIZONTAL FULCRUM PIN

The purpose of research is increase in effectiveness of pumping of honey in the separator of radial type with a horizontal spin axis of a rotor. Use radial a separator allows to make honey pumping on both sides of a frame at once and places larger quantity of a frames. The radial separator consists of housing and a rotor. The rotor is set in motion via the belt drive manually or the electric motor. The rotation frequency of a rotor of a separator is the major technology factor influencing honey pumping process. With increase in a rotation frequency the centrifugal force providing a honey exit from honeycombs of a frame increases. The high rotation frequency of a rotor with a framework, can lead to destruction of a wax basis of a cellular frame. Low the rotation frequency can become the reason of inexact pumping of honey from honeycombs. In the course of centrifugation the honey which is contained in everyone unit is affected by the gravity, a centripetal force, tangential force of shift of layers of honey, force of reaction of walls of honeycombs. As a result of calculation it is established that the rotation frequency of a rotor depends on such parameters as viscosity of honey, geometrical parameters of honeycombs, distances of honeycombs from a separator rotor spin axis. In the course of work there will be first of all a honey honeycombs located further from a rotor axis. Decrease in cooperative weight of a frame will allow to keep its wholeness and to gradually increase a separator rotor rotation frequency.

CHOOSING AN OPTION FOR PLACEMENT OF THE DYNAMIC VIBRATION DAMPER FOR THE ELECTRIC CENTRIFUGAL PUMP

The frequency of oscillations appearing during the electrical centrifugal pump operation is related with the rotor rotation frequency and is actually constant. To reduce the vibration of the constructions critical components the dynamic dampers are often used when vibration is transferred from the protected machine to the auxiliary assembly which vibration poses no danger to the system as a whole. The paper discusses the possibilities of this idea implementation for protection of the electrical centrifugal unit and presents three possible options for consideration.

Links between Main Frequencies of Established Rotating Stall and Rotational Frequencies and/or Blade Passing Frequencies

The ratios between the main frequency of rotating stall and rotational frequency may be considered in the form of exact ratios of small natural numbers if the pressure signals in compressors during rotating stall include the rotor rotation frequency component. During rotating stall in compressors with good rotor balancing (with absence of the rotational frequency component in the frequency characteristics of pressure signals), these ratios between the main frequency of rotating stall and rotational frequency are or are not in the form of ratios of small natural numbers. The experimentally received characteristics of power spectral density of pressure signals also show the presence of components with combinations of blade passing frequency and different harmonics of main rotating stall frequency.