JPH0353211B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic excitation device used to excite a main heavy body (host mass) used in a vibrating conveyor device, a bin hopper, and a chute used, for example, in transporting and weighing bulk materials. Concerning vessels.

Electromagnetic vibrators are widely used in the industry to facilitate the flow of bulk material from storage bins, hoppers and shipping chutes. Electromagnetic vibration is also used in vibrating feeders for feeding various bulk materials to mixers, crushers, crushers, packaging machines, batching, grading, or mixing departments. A device is used.

Generally, an electromagnetic drive vibration system is a two-weight design, with one weight carrying the electromagnet and the other weight carrying the armature. The two weight bodies are typically connected by a spring dimensioned to create a resonant amplifying motion in the system. The electromagnet has magnetic pole faces approximately 1/10 inch (2.54 inch) apart from each other.
mm) or less. The traction force increases in almost inverse proportion to the square of the gap. The motion of the system is inversely proportional to the weight2
The weight is distributed among two bodies, meaning the lighter weight moves proportionately faster. As the gap between the pole faces increases or decreases, the weight moves in opposite directions.

Therefore, there is a need for a device that prevents the pole faces from colliding when they approach the minimum gap and the magnetic force approaches its maximum value.

According to the invention, an electromagnetic excitation device comprising a vibrator body having a plurality of inwardly oriented electromagnetic devices and a free weight body supported for longitudinal movement within said vibrator body. a non-linear spring device carried within the exciter body, the non-linear spring device being laterally and longitudinally proximate to the adjacent electromagnetic device and in contact with the free weight body; An electromagnetic exciter is provided characterized in that it includes a contact surface.

Embodiments of the invention provide an electromagnetic exciter incorporating a completely enclosed free weight body carried within an elongated housing. The housing is
It includes a pair of terminal caps, each receiving an implanted magnet. The terminal caps are separated by a housing tube mounted therebetween.

The free weight is suspended by elastomeric shear springs in the housing tube, equidistant from each end cap. A pair of armature assemblies are integral with the free weight, generally one at each end of the elongated free weight.

A compression element is interposed between the free weight body and the electromagnet holding end cap, typically spaced therefrom. These nonlinear springs help avoid armature collisions and also store input energy during electromagnet conduction, resulting in high efficiency.

The electromagnets are sequentially energized by a remotely located controller connected to the first electromagnet holding terminal cap. An armored conduit extends from the first terminal cap to the second terminal cap. When the electromagnet is continuously energized, the free weight moves vertically within the housing and contacts the compression element, and periodically moves back and forth as the electromagnet is energized and deenergized. The frequency of operation is close to the wide range of natural frequencies of the driven heavy object using resonance.

The apparatus and operation of the present invention will now be described with reference to the accompanying drawings.

Bulk material transport trough (gutter) 10 shown in Figure 1
is a typical use of the electromagnetic vibrator of the present invention. The exciter 12 is attached to the trough by devices such as fasteners 14. Conduit 16 extends from the electromagnetic exciter to a control module, typically located at a remote station.

The mechanical aspects of the invention are readily understood by examining FIG. 2, which is a perspective view of electromagnetic vibrator 12. The shaker is a unitary, closed construction having a housing tube 20 made of a durable construction material such as aluminum. First and second terminal caps 22, 24 each function as a magnet housing for housing an implanted electromagnet, such as 26 within cap 24. terminal cap 2
2 and 24 are attached to both ends of the housing tube 20. In one embodiment, fasteners, such as studs 32, such as 30, are used to secure the rigidity of the housing. The housing is structurally an elongated container that is sealed against intruders. This container-like housing can provide an explosion-proof housing not possible with conventional electromagnetic exciters.

Power supply conduit 16 to first terminal cap 22
A conduit terminal 28 is provided for receiving the conduit terminal 28 . FIG. 5 shows a conduit 34 extending between the first and second end caps 22, 24 to carry the wire bundle used to provide electrical pulses to the electromagnet 26.

A threaded hole such as 40 is also provided in the first place to provide one way to attach the electromagnetic exciter 12 to the vibrating device.
It can be provided in the terminal cap 22 of.

Referring to FIGS. 2, 3, and 4, the components held securely within the housing are identified. Electromagnet 26 as well as its counterpart (not shown) carried on the opposite end of housing tube 20
The cover plate 42 is shown clearly as well as the power supply wires from the wire bundle 36.

At each terminal cap in the housing tube,
Mounted on the body system are each pair of compression elements, such as identical elements 44, 46, which constitute spring elements that function as non-linear elements. The thicknesses of these two pairs of compression elements are different.

The first set 44 of elastomeric compression springs is adhesively or otherwise attached to a backing plate, such as 50, which is attached by an attachment device to the inner surface of the end cap at each end of the housing tube. The fiber reinforcement cap may be integrally formed with the elastomeric body portion. The cap eliminates relative movement between the elastomer and mounting plate 76 during compression of the spring. The second set of elastomeric compression elements 46 is suitably attached to a similar backing plate, although shims such as 52 may be interposed between the backing plate and the attached end cap. Elastomeric compression elements 44, 46 are symmetrically arranged with paired elements on diametrically opposite sides of the longitudinal housing axis. The thickness of the elastomeric compression element and associated shim may be varied to provide the desired operating characteristics for a particular electromagnetic exciter. The stack height of each elastomeric compression element at each end of the housing can also be different from other sets at the same end to allow better adjustment of the non-linear characteristics of the spring device. The elastomeric compression element provides nonlinear stiffness and self-limiting deflection of the device.

The top surface of the elastomeric compression element, indicated by reference numeral 44, may be a raised surface (curved surface) so that the thickness of the compression element is non-uniform along the length of the element. FIG. 8 shows an elastomeric compression element 100 having a raised portion 102, which, although the degree of curvature is exaggerated, provides a good representation of the concept. Of course, it is also possible to provide the elastomeric compression element with a plurality of ridges or depressions, thereby providing a more defined boundary between the thicker and thinner parts of the elastomeric compression element.

According to alternative embodiments, fewer or more elements than the four elements used in the preferred embodiment shown herein may be used. Still other embodiments of elastomeric compression elements may also be used. By way of example, a one-piece ring-shaped elastomeric compression element 104 as shown in FIG. The armature 80 may have any profile capable of accommodating the armature 80, which does not necessarily have to be rectangular as shown. This elastomer ring is
For example, it may be suitably attached to a shim 52 or, in some cases, to a single support plate, indicated by reference numeral 108. The corner support plate may take any form that allows the ring or element 104 to be attached directly to the inner surface of the terminal cap or to the mounting plate 76.

FIG. 10 is a side elevational view, partially in section, of the element shown in FIG.
10, and the step portion is indicated by the instruction number 112.
The contours of the tops of the elements can be of various shapes, for example they can be flat surfaces, corrugated surfaces with ridges and depressions of various sizes in the circumferential direction of the ring, or they can be of various shapes throughout the ring. It may be a stepped surface with a height of . The element shown in FIG. 10 is not shown in a limited manner, but merely exemplifies an element having an undulating surface. These elastomeric rings may be provided with integral end caps of fiber reinforced material.

It should be noted that the housing tube and end cap and all the devices and parts described above are integrally combined in the assembled embodiment and thus form part of the driven weight within the vibration system.

A free weight 60 is contained and suspended within the housing tube 20 between the end caps 22,24. Figures 2 and 3 are helpful in identifying the parts. First and second shear springs 54,5
6 is press fit into the elongated housing tube 20 to suspend the free weight body 60.

The free weight body includes a central member 62 of generally elongated form having a windowed wall portion defining a pair of recesses such as 64. The free weight is supported and operably attached to the inner bores of the first and second shear springs. A threaded rod 66 for holding an adjustment weight such as 70 secured by a fastener.
A holding device such as the following is provided.

Adjustment weights, as indicated by reference number 70, are important interchangeable elements for the present invention, allowing for changes in the free mass while keeping the overall dimensions and component configuration of the electromagnetic exciter constant. be. The adjustment weight can be changed during resonance adjustment without having to change or adjust the spring rate of the supporting shear spring. Thus, exciters of different capacities can be fabricated from common parts and the economies of equal dimensions can be advantageously exploited. Free weight body and shear spring 54,5
Correct selection of the 6 natural frequencies allows universal resonance tuning. This universal resonance adjustment allows the exciter to produce its rated output independent of changes in the weight of the driven member to which it is attached.

After the adjustment weights are attached, flange plates such as 72 are attached to opposite ends of the center member 62 in any suitable manner. An armature assembly 74 including a mounting plate 76 and a generally rectangular armature 80 is attached to the flange plate 72.
is combined with As an alternative method of assembly, the mounting plate 76 may be omitted and the armature may be mounted directly to the flange plate 72.

When the electromagnetic exciter is assembled, there is a gap 82 between the surface of the armature 80 and the surface of the electromagnet 26 in a stationary state.
exists. During operation, the clearance increases and decreases periodically, but if the correct nonlinear spring is selected,
The magnetic pole faces do not collide.

As is apparent from the drawings, the internal parts of the housing tube are symmetrically identical on both sides of the steel central member. The symmetry of this construction and the two opposing electromagnets are advantageous when the exciter is activated. FIGS. 6 and 7 are graphs illustrating the advantages achieved by the embodiments herein.

FIG. 6 graphically displays the benefits of universal resonance tuning of the exciter. The frequency ratio on the X-axis indicates that the maximum amplitude occurs when the operating frequency of the shaker and the natural frequency of the system are equal. The portion of the curve contained between A and B represents the operating band for one free weight exciter applied to a wide range of driven weights. The exciter is resonantly tuned by properly selecting the tuning weights so that the natural frequency of the system is equal to the operating frequency of the exciter. This means adjusting the shaker so that the frequency ratio is between A and B over a wide range of driven weights. The resonance amplification factor in this range is at least 5.

The exciter continues to operate effectively up to the point of superresonance indicated by the point where straight line B intersects the curve. The resonance amplification factor is again 5. In other words, it is clear that this vibrator is close to resonance over a wide weight range of the driven heavy body.

Without the compression element, the pole faces would collide with a higher amplification factor. Line C shows the total excursion of the system maintained by these elements.

In FIG. 7, the timing of the power pulses and the force produced by the electromagnet are shown graphically. Each electromagnet is energized once per machine cycle. Although not shown in the drawings, a controller is mounted remotely from the exciter and is designed to sequentially supply each electromagnet with properly timed pulses of electrical energy to energize each electromagnet. The rest clearance A on the right side of the graph indicates the position where the free mass of the armature is equidistant from the electromagnet. Looking towards the minimum gap on the left side of the graph, the time of the electrical pulse to the electromagnet is shown by the curve represented by dashed line C. The force produced by the electromagnet is shown by curve D, and the area under this curve is the output energy of the magnet. During the deflection of the free mass toward the electromagnet, the electromagnet is kept alive from E to B (minimum gap). When the gap opens, the current continues to flow until it returns to point F, so the net energy generated is the hatched area below the curve.
This energy is stored in compression springs 44,46. Electromagnets designed to be harnessed in the manner described above allow significantly more energy to be stored per cycle than conventional designs.

Due to the design of the compression element, this stored energy obtained by the initial impact of the free mass towards the compression element provides approximately 30% of the force required to accelerate the free mass in the opposite direction. Thus, power savings and associated cost benefits are obtained. Since compression springs are non-linear, armature collisions can all be avoided by correct selection of the elements.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a feeder trough with an electromagnetic exciter installed; Fig. 2 is an exploded view of the inventive exciter with some parts cut away; Fig. 3 is for clarity. 2 is a front view of the device shown in cross section with some parts cut away; FIG. 4 is an end view of the device of FIG. 2 with parts of the housing cut away and shown in cross section; FIG. is a side view shown on line 5-5 in Fig. 4, Fig. 6 is a graph showing the frequency response band of the electromagnetic exciter, Fig. 7 is a graph showing the energy output of the electromagnetic exciter, and Fig. 8 is a graph showing the energy output of the electromagnetic exciter. 9 is an elevational view of an elastomeric compression element, FIG. 9 is a plan view of an elastomeric ring, and FIG. 10 is a partially sectional elevational view of the ring shown in FIG. 10...Trough (gutter), 12...Electromagnetic exciter,
20...Housing, 26...Electromagnet, 44,4
6...Nonlinear spring device, 60...Free weight body.

Claims (1)

[Scope of Claims] 1. An electromagnetic excitation device comprising a vibrator body having a plurality of inwardly oriented electromagnetic devices, and a free weight body supported for longitudinal movement within the vibrator body. The vibrator includes a non-linear spring device carried within the vibrator body, the non-linear spring device being laterally and longitudinally proximate to the adjacent electromagnetic device and in contact with the free weight body. An electromagnetic exciter characterized by having a contact surface that 2. The electromagnetic vibrator according to claim 1, wherein the nonlinear spring device is an elastomer compression element having a curved surface, and the contact surface is curved. vessel. 3. The electromagnetic vibrator according to claim 1, wherein the contact surface of the nonlinear spring device is an elastomer compression element in which raised portions and recessed portions are alternately provided. Shaker. 4. The electromagnetic vibrator according to claim 1, wherein the contact surface has a step. 5. The electromagnetic vibrator according to claim 1, wherein the nonlinear spring device is an elastomer ring. 6. The electromagnetic vibrator according to claim 5, wherein the elastomer ring has alternating raised portions and recessed portions over its entire area. 7. The electromagnetic vibrator according to claim 5, wherein the elastomer ring has a step surface having undulations over its entire area.