SU775638A1 - Device for determining mechanical characteristic rigidity of executive motor - Google Patents

Description

nor in connection with the necessity of consistent measurement at several points of the characteristic (at least three). In addition, in such a device it is difficult to measure the mechanical characteristics of an engine with a limited angle of rotation, since in this case, due to the presence of a stop, the engine during acceleration cannot reach the established speed of rotation.

The purpose of the invention is not expanded the field of application of the device, as well as the acceleration of the measurement process.

This goal in the device of the present invention is achieved due to the fact that the meter brake is made in the form of an oscillating mechanical system connected to the angle of rotation sensors, and the input source is in the form of a generator: sinusoidal oscillations.

FIG. 1 is a diagram of a device with a mastic oscillating system; in fig. 2 - a constructive kind of device with a balanced oscillatory system.

The device according to the present invention comprises an input signal source 1, which is a sinusoidal oscillator, amplifier 2 of the input signal power. The shaft 3 of the engine under test 4 is connected to the measuring brake 5. The measuring brake 5 is made in the inside of the cylinder with a weight b on the rocker arm 7, the end of which is connected to the springs 8 and 9 mounted on the fixed base 10. The angle of deflection of the idol is measured by sensor 11.

Measuring brake 5 can also be made in the form of a disk 12 connected to a coil spring 13 (Fig. 2). Instead of the spring 1 3, a torsion bar or other elastic element can be applied, however, in any case, the engine can be tied to a mechanical oscillator on the system.

The device works as follows.

When a sinusoidal input signal and W are fed from the generator, the motor 4 causes the oscillatory motion, the amplitude of which is measured by the sensor 11. If the frequency of the input signal UBX is equal to the resonant frequency of the mechanical system p, then at the moment of resonance

where Mr is the starting torque of the engine, is the sought rigidity of the mechanical characteristics of the engine,

C - the angle of rotation of the shaft dvigd4

-sch- rotation speed.

For a sinusoidal oscillation mode, the resonance moment with amplitude if /

 - Therefore, fA - | biUp fp. Where the comma stiffness is

Wn

 -

  Thus, the sought-for stiffness of the mechanical motor characteristic is calculated by the formula (3) from the known resonance frequency UJp, measured amplitude of the angle Pr in the resonator torque, and the known starting torque Mg (. The starting torque can be measured previously using the same device by angle deviation of the tandem when applied to the input of the motor voltage.

The validity of the formula ()) follows from the following dependencies. The timing of the moments on the engine shaft with the consideration of the tandem has the form

aTcif- - 3S where 3 is the moment of inertia of the tandem

taking into account the rotor of the engine; moment created when the deviation of the tandem

, esin4- Ch.1nCH-X (Qe.) C5)

In the last equality for small angles M, the principle is g-in -HF and denoted ° where G is the load weight b,

t is the load shoulder, O is the stiffness of the springs 8 and 9, is the distance from the point of attachment of the springs to the shaft 3.

Substituted the expression (5) in (4) and the transition to the Laplace transform, we get

) 4 (s)

The modulus of this expression is

/ W / + Ch) 4 (.р, и; Ч, П)

where W - circular oscillation frequency. At the resonant frequency i-O - loV

, - V-SusEi;

lA)

se)

there is a maximum deviation of the Chr tomb and from expression (7) we get

(--p.i; pp, W

which corresponds to equations (1) and (2).

Selecting the design parameters of the G, C; 6, fi, it is possible to determine the stiffness of the mechanical characteristic at any limited angle of rotation of the motor shaft for any speed of interest and different input voltages of the motor.

The advantage of the device according to the present invention is that it can be used for engines with a limited angle of rotation, for low-speed torque engines having a high torque and low speed will turn, as well as for executive engines of all other types.

Another advantage of the device is the acceleration of the measurement process, since in order to determine the rigidity of the mechanical characteristic at any point, only one measurement of the amplitude of the deviation angle of the instrument at the moment of resonance is sufficient.

Claims (3)

1. USSR author's certificate 0 W 16654I cl. G About G 7 / 18,04.10.62. 2. Rabkin G.L. Experimental study of shipboard automatic systems. L., Shipbuilding, 1966, p. 207. five 3. Authors certificate of the USSR 241766, cl. G 01 L 3 / 20.05.09.67 (prototype). eleven