RU2263988C2 - Dc electromagnet with sectional disposition of coils - Google Patents

Abstract

FIELD: electromechanics; dc plunger electromagnet with two winding coils.

SUBSTANCE: proposed dc electromagnet that has plunger, case, fixed core, and coils wound of insulated wire on two different sections; coils are differentially interconnected. One of coils encloses plunger and other one, fixed core. Intermediate flange is disposed between coils. Plunger traction characteristic affords utmost tractive force at maximal working air gap which increases with its decrease thereby eliminating chatter and electric arc.

EFFECT: enlarged functional capabilities, enhanced vibration resistance.

1 cl, 2 dwg

Description

The invention relates to electromechanics, in particular to the design of a DC electromagnet with a retractor armature and two sections of windings.

Known DC electromagnet (Japanese patent No. 49-15310, IPC H 01 F 7/13), with a retractor armature, which has a winding divided into two sections, between which an intermediate flange is located. This design allows you to get increased traction on large working gaps.

As a prototype of the proposed device, the design of the electromagnet, known from French patent No. 2553567, IPC N 01 F 7/13, is used, in which for the reliable operation of the retractable electromagnet with an intermediate flange and a sectional arrangement of windings as a power electromagnet in the automatic gearbox of a car, the ratios are patented the size of the magnetic system. With the aspect ratio of patent No. 2553567, it is possible to obtain a part of the traction characteristic of an electromagnet with a negative slope, i.e. as the working air gap decreases, the force of the electromagnet also decreases.

A disadvantage of the known design of the electromagnet is the insufficient length of the traction characteristic, which has a negative slope, because as the anchor approaches the fixed core, the pulling force again increases sharply.

The objective of the invention is to expand the scope by creating a retractable DC electromagnet with a traction characteristic that has the greatest traction at the maximum value of the working air gap and decreases when it decreases.

The problem is solved in that in an electromagnet with an intermediate flange and two windings, wound separately in each section and located on opposite sides of the intermediate flange, the windings are connected counter to each other. The traction characteristic of the electromagnet, having a negative slope, allows the use of an electromagnet as a device that allows you to adjust the position of the armature by changing the ratio of the magnetizing forces of the windings. This change can be made by increasing or decreasing the current in one of the windings.

Figure 1 schematically shows a General view of the electromagnet in the context, figure 2 is a counteracting characteristic (graph I) of the return spring (not shown in figure 1) and traction characteristics of the electromagnet with an intermediate flange and onward windings (graphs II, III, IV) at different ratios of the magnetizing forces of the windings IW1 / IW2 = K (X1, X2, X3 - stable positions of the armature when changing the ratio of the magnetizing forces of the windings).

The DC electromagnet (Fig. 1) contains a retractable armature 1, housing 2, a fixed core 3 and windings from an insulated wire located in two different sections. One of the sections of the windings 4 covers the armature 1, the other section of the windings 5 has a fixed core 3. An intermediate flange 6 is located between the sections of the windings. The windings 4 and 5 are connected opposite to each other.

When the electromagnet is turned on, the current flowing through the section of the winding 4, covering the armature 1, creates a magnetic flux Ф ₁ , and the current flowing along the section of the winding 5, covering the fixed core 3, creates a magnetic flux Ф ₂ . Since the sections of the windings 4 and 5 are turned on in opposite directions, the flows Ф ₁ and Ф _{2 are} directed towards each other.

The force of the electromagnet F is determined by the magnitude of the magnetic flux F ₁ exiting from the end of the armature 1 into the working air gap, which according to Maxwell’s formula is equal to:

F = Ф ₁ ² / 2μ ₀ S _δ ,

μ ₀ - magnetic permeability of air;

S _δ is the area of the air gap.

At the initial working clearance, the magnetic flux f _{1 is} maximum, which determines the maximum traction force of the electromagnet. When the armature 1 approaches the intermediate flange 6, the magnetic flux Ф ₁ decreases due to the increasing influence of the magnetizing force created by the current passing through the turns of the section of the winding 5, covering the stationary core 3. This magnetizing force creates a magnetic flux Ф ₂ , which is directed towards the flux Ф ₁ . The smaller the distance between the end of the armature and the intermediate flange, the stronger the demagnetizing effect of the winding 5 and the smaller the magnitude of the magnetic flux f ₁ , which creates the force of the electromagnet.

Using the on-off switching of the windings 4 and 5 and changing the ratio of their magnetizing forces, you can get a family of traction characteristics (figure 2), where the force of the electromagnet decreases with a decrease in the working air gap throughout the course of the armature 1. This allows you to get several opposing forces stable positions of the anchor 1 when it moves along the working air gap.

Sources of information

1. Japan patent No. 49-15310, IPC H 01 F 7/13.

2. French patent No. 2553567, IPC H 01 F 7/13.

Claims (1)

A DC electromagnet with a sectional arrangement of windings containing a retractable armature, a housing, a fixed core and windings from an insulated wire located on two different sections, between which an intermediate flange is located, one of the sections covering the armature and the other a fixed core, characterized in that the windings are turned on against each other.

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