SU1051431A2 - Tachometer using barkgausen effect - Google Patents

Description

110 The invention relates to the measurement of rotational speed. According to the main author. St. No. 530253 is known as a tachometer containing a pole rotor, a stator and a registering device connected to the stator winding. The stator is made in the form of a non-magnetic base and an annular ferromagnetic core with a uniform winding. The ferromagnetic core is made in the form of a spiral, the length of which is a multiple of the length of the stator core. The stator winding may be located on the middle turns of the helix. The disadvantage of the known tachometer is the relatively narrow working range of measured speeds. This is due to the fact that, for any fixed number of rotor poles and turns of the stator core helix, increasing the rotor speed first reduces the tachometer characteristic slope and then decreases the EMF from the stator winding output to almost zero. This type of output characteristic of the tachometer is explained by the fact that at high rotational speeds of the rotor, the intensity of the Barkhausen jumps greatly increases, and, consequently, the probability of coincidence and mutual compensation of individual polarized pulses increases. The purpose of the image is to expand the working range of measured angular velocities. The goal is achieved by the fact that a tachometer comprising a case with a pole rotor installed in it and a stator core made in the form of a spiral with a uniform winding located on the middle turns of the stator spiral is additionally equipped with a rotor axial movement mechanism and a rotor position lock, and a spiral the stator core is made with variable pitch, with the maximum pitch of the spiral stator core equal to the length of the rotor. FIG. 1 shows the tachometer design; in fig. 2 - its output characteristics. The tachometer includes a cover 1 with two bearings 2, an input shaft 3, a dielectric frame with a stator core 5, body 6, an axial movement mechanism of the rotor, made, for example, in the form of a sleeve 7 2 and a retainer containing a ball 8 with a spring 9, and a pole rotor 10. The spider 5's spindle core is made with variable pitch, and the rotor 10 is rigidly connected to the sleeve 7. In order to simplify the drawing, the recording equipment and the stator winding in FIG. not shown. Tachometer works as follows. When the shaft 3 rotates at an angular velocity SL), the sleeve 7 with the rotor 10 also rotates. As a result, the ferromagnetic stator core 5 is re-magnetized by the moving gradients of the rotor field 10, and in the stator winding there is an emf from Barkgausen jumps, the root mean square value proportional to the angular velocity of the rotation. If the rotor 10 is in the position shown in Fig. 1, which corresponds to a portion of the stator core 5 with a minimum pitch, then the maximum number of turns is laid on the length of the rotor 10. in the stator core 5- This position of the rotor 10 corresponds to a characteristic with a certain steepness and a certain working range. If necessary, increase the working range move the sleeve 7 with the rotor 10 in the direction of its extension from the housing 6 until the ball 8 enters the shaft cavity 3 corresponding to the required working range. In this case, the rotor 10 moves to a zone with a large pitch of the stator core 5, as a result of which a smaller number of core 5 turns are placed on its length. This leads to a decrease in the steepness of the output characteristic and to an increase in the operating range, since the distortion of the output characteristic of the meter occurs at a higher angular velocity. The maximum operating range is achieved when one turn of the stator core 5 is laid along the length of the rotor 10. In FIG. Figure 2 shows a family of tachometer characteristics taken at three different positions of the rotor 10. Curve a corresponds to the extreme left position of the rotor 10; curve 6 - the average position; curve D - the extreme right position.

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The use of the proposed tacho-operating range and, thus, the size gauge will allow, by simple adjustment of the working range of the measured angles, to adjust it to the desired velocity.

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Claims (1)

TACHOMETER USING THE BARKHAUSEN EFFECT by ed. St. No. 530253, · characterized in that, in order to expand the operating range, it is additionally equipped with a rotor axial movement mechanism and a rotor position lock, and the spiral stator core is made with a variable pitch, while the maximum pitch of the stator spiral core is equal to the length of the rotor. 1 1051431