SU678215A2 - Electromagnetic powder brake - Google Patents

Description

The invention relates to mappings, in particular to ferro-powder brakes and couplings, and can be used in damping devices of automation systems. Known electromagnetic powder brake on the main ed. St. No. 517721, which contains a magnetic pipe with an excitation coil and an annular working cavity filled with ferromagnetic powder, in which a hundred-channel-shaped rotor is placed, having openings at the base of the wall and a groove on the outer and inner cylindrical surfaces. The grooves are made along a helical line and have the opposite direction. The disadvantages of the brake should be attributed to the poor mixing ferroporushka near the surface of the magnetic circuit, as well as a relatively low braking torque. The smooth surface of the magnetic circuit reduces the magnitude of the magnetic induction gradient and the corresponding magnitude of the magnetic forces, which, in turn, leads to a decrease in the braking torque. The purpose of the invention is to increase the brake torque by improving the mixing of the ferromagnetic powder. The goal is achieved by the fact that on the working surface of the magnetic circuit is made along the SCREW line. FIG. electromagnetic powder brake in longitudinal section; in fig. 21c, FIG. one; .on FIG. 3 and 4 - opposite rotor and magnetic cores in two; working positions The brake contains a magnetic core 1 with an annular working cavity, on the working surface of which grooves are made along a spline line, coil excitement 2, separated from the working gap by a non-self-contained gasket 3, a curved rotor 4 with openings 5 at the base of the wall and ankami oppositely directed cuttings on the outer and inner cylindrical surfaces. The rotor is fixed on the output shaft 6, and the seal 7 serves to protect the flan1 @ th bearing assembly 8 from penetration of ferropowder ..,

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Electrolipotency powder brake works as follows.

When driving to the excitation coil 2 of direct current, the magnetic flux F penetrates the external and internal working gaps between - j the magnetic core 1 and the rotor 4, resulting in a ferroporous porosity in the gaps, 1 turns into a plastic mass with a sdang resistance / dependencies On inductive magnetic field and its heterogeneity.

When the rotor 4 rotates, the plastic mass begins to circulate along the gaps under the influence of mechanical forces, such as the screw effect, caused the rotor thread, as well as the lightning forces, caused by the mutual distribution of the grooves on the rotor and magnetic core.

In order to clarify the effect of magnetic forces, we consider two positions of the rotor (Figs. 3 and 4).

Suppose that the labels on the outer surface of the rotor HMeiot are left-handed and the grooves are 20 idt and the opposite surface of the magnetic circuit is right. FIG. Figures 3 and 4 show the rotor rotor (Ф А) and the magnetic conductor (Ф Б), intersecting under a certain J Tl, which depends on the cutting pitch, angle of inclination and diameter of the grooves. In the working gap, at the intersection of the teeth (silted; part in figs. 3 and 4) ey TlSpMiG Shmaximal, cijotBetciBeHHo here will act maximum magnetic forces, h 30 causing thickening of the ferromagnetic powder particles.; 6, then ferromagnetic powder. By the action of the pshekovy effect of the rotor thread, 35 is moved along the outer surface of the roto ja from its bHB to the ertj end. With

the rotor at a certain angle (fig. 4) the point where the rotor teeth and the magnetic core intersect move along the magnetic circuit teeth. As a result, the maximum of the magnetic induction in the working gap moves, along with which the particles of the ferromagnetic powder move under the action of tangential forces. Moreover, the direction of this movement coincides with the direction of movement of the powder particles under the action of mechanical forces due to the screw effect of the thread.

A similar phenomenon occurs in the internal, rhenium gap, only the movement of particles of ferromagnetic powder will be from the end to the base of the rotor.

The outer and inner gaps are interconnected by means of an end gap (between the end of the rotor and the end portion of the annular working gap of the magnetic circuit 1). and a number of holes at the base of the rotor, the number and profile of which are selected constructively.

The grooves on the working surface of the magnetic circuit, produced in a helical line, make it possible to improve the mixing of the ferromagnetic gyuroshka in the working gap by increasing the tangential magnetic forces acting on the shredder and promoting its movement in the gap, and increasing the specific braking torque by 10-15% due to the increase magnetic induction gradient in the working gap. F o rm u la invention

Electromagnetic powder brake auth. St. No. 517721, distinguished by the fact that in order to increase the braking moment by improving the mixing of the ferromagnetic powder, the working surface of the magnetic circuit is made along a helical line of the groove.

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