SU708226A1 - Rotational speed meter - Google Patents

Description

(54) ROTATION SPEED METER

The invention relates to a measurement technique, can be used to measure the speed of rotation of various and mechanisms.

Analog speed sensors are known that convert the rotational speed into an electrical signal 1.

Closest to the proposed izdeletel of rotational speed, a contactless tachogenerator of a constant, containing two asynchronous electrical machines, the rotors of which are interconnected and with the test shaft. The multiphase excitation winding of the first machine is connected to a power source, the rotor windings are interconnected, and the reference voltage winding on the stator of the first mashina and stator winding of the second machine is connected via a rectifier to the subtractor and the recording device.

The disadvantages of the prototype include the dependence of the output signal on the change in the excitation voltage,

and other destabilizing factors.

The purpose of the invention is to improve the measurement accuracy by eliminating the influence of destabilizing factors.

The goal is achieved by inserting an addition unit into the rotational speed meter connected to the rectifier outputs, a multiplication unit whose inputs are connected to the inputs of the subtraction and addition blocks, and the output. connected to a registering device, the multiphase field windings of the machines are connected to a power source with direct and reverse phase alternation,

The circuit for measuring the rotational speed is shown in the drawing.

Claims (2)

The device consists of one power supply source 1, two electric machines of alternating current 2 and 3, two rectifiers 4 and 5, subtraction unit 6, addition unit 7, multiplier 8 and recording device 9. The windings are first electric the machines are connected to a power source with direct alternation of phases, and the second machine with reverse alternation, blah) the gift of which the magnetic excitation fields in the machines rotate in different directions. The rotors of the machines are mechanically connected with each other and, with changes, they are connected to the shaft under study. The output windings are connected to rectifiers whose outputs are connected to lamination and subtraction blocks. The outputs of the lagging and subtraction blocks of the transducers to the input of the multiplication unit, at the output of which an electrical signal is generated, is proportional to the rotational speed, and is intended by the recording device. At an angular velocity equal to zero, in the output windings of electric machines the initial voltages wives whose amplitudes due to the identity of the machines are identical. Therefore, the output voltage of the subtraction unit is zero, and the block of addition is double the initial voltage. When the angular velocity is not equal to zero, in one electric machine of the angle the rotational speed is combined with the angular velocity of rotation. The field of excitation, and in the other - is subtracted, i.e. U r -cCuj j -uj pV-, k is the coefficient of projectivity angular rotational speed of the FIELD - angular rotational speed of the Voltage at the outputs of the circuits subtracting Up Up and adding USir -i and -i and bp, 2 By multiplying the diffusion signal by an amount opposite to the total signal, we obtain at the output of the circuit: (B1X (-3 constant coefficient ()) s; ient. G1; .1and exposure to distbilitis (flowing factors the stresses of U and Og are incremented; C, C, D, I; 1, In this case, the output; for example, the subtraction and addition schemes have the form: I O p - and - U, -v (i,.),)) S - and - with and -V li,) - 2 (yyoi y.), output voltage circuits. multiplication; and - - --k TbblA IJc 1 o Consequently, despite the impact of destabilizing factors, the output voltage of the meter remains proportional to the rotational speed. Claims An rotational speed meter comprising a power source, two AC electric machines with multiphase excitation windings, the rotors of which are rigidly connected between soybeans, and the output windings are connected via rectifiers to the subtraction unit, and a recording device that differs; that in order to increase the measurement accuracy by eliminating the effect of destabilizing flckoo poBj, an addition block was inserted into it, connected T: to the strands of rectifiers, and a multiplication unit, whose inputs were combined with the outputs of the subtractor and the layer, and the output connected with a registering device, in which the multiphase excitation windings of the machines are connected to a power source with direct and reverse HLJM phase alternation. Sources of information taken into account in the examination 1. Tun A, R. Tachogenerators for electric drive control systems ,. M, 1964, p. 4O-57. 2. USSR author's certificate N9 539358, cl. QO1 P 3/46, 1974, (protot p).