CA1253189A - Electromagnetic vibratory exciter - Google Patents
Electromagnetic vibratory exciterInfo
- Publication number
- CA1253189A CA1253189A CA000475920A CA475920A CA1253189A CA 1253189 A CA1253189 A CA 1253189A CA 000475920 A CA000475920 A CA 000475920A CA 475920 A CA475920 A CA 475920A CA 1253189 A CA1253189 A CA 1253189A
- Authority
- CA
- Canada
- Prior art keywords
- elastomeric
- accordance
- compression means
- elastomeric compression
- portions
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K33/00—Motors with reciprocating, oscillating or vibrating magnet, armature or coil system
- H02K33/12—Motors with reciprocating, oscillating or vibrating magnet, armature or coil system with armatures moving in alternate directions by alternate energisation of two coil systems
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
- B65G27/00—Jigging conveyors
- B65G27/10—Applications of devices for generating or transmitting jigging movements
- B65G27/16—Applications of devices for generating or transmitting jigging movements of vibrators, i.e. devices for producing movements of high frequency and small amplitude
- B65G27/24—Electromagnetic devices
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K33/00—Motors with reciprocating, oscillating or vibrating magnet, armature or coil system
- H02K33/02—Motors with reciprocating, oscillating or vibrating magnet, armature or coil system with armatures moved one way by energisation of a single coil system and returned by mechanical force, e.g. by springs
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Mechanical Engineering (AREA)
- Apparatuses For Generation Of Mechanical Vibrations (AREA)
- Jigging Conveyors (AREA)
- Reciprocating, Oscillating Or Vibrating Motors (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An electromagnetic vibratory exciter includes an exciter body with a plurality of electromagnets directed toward the inside of the exciter body. A free mass is supported for longitudinal movement in the exciter body.
A non-linear spring is carried inside the exciter body inboard and longitudinally adjacent one of each of the plurality of electromagnets. The non-linear spring has contoured surfaces. The vibratory exciter is used for imparting vibratory excitation into a host mass for use in conveyor equipment, bin hoppers and chutes for bulk material.
An electromagnetic vibratory exciter includes an exciter body with a plurality of electromagnets directed toward the inside of the exciter body. A free mass is supported for longitudinal movement in the exciter body.
A non-linear spring is carried inside the exciter body inboard and longitudinally adjacent one of each of the plurality of electromagnets. The non-linear spring has contoured surfaces. The vibratory exciter is used for imparting vibratory excitation into a host mass for use in conveyor equipment, bin hoppers and chutes for bulk material.
Description
~5~ g ELECTROMAGNETIC VIBRATORY EXCITER
The invention concerns electromagnetic vibratory exciters for use in imparting vibratory excitation into a host mass for use, for instancel in vibratory conveyor equipment bin hoppers and chutes for bulk material transport and metered delivery.
Electromagnetic vibratory drive units have been extensively used in industry to ensure the smooth flow of bulk material from storage bins, hoppers and delivery chutes. Electromagnetic vibratory drive units are also used in vibratory feeders for feeding various bulk materials to mixers, grinders, crushers, packaging machinery, batching, grading or mixing stations. The electromagnetic exciters are coupled to a delivery trough which is vibrated by the exciter to control material flow along the chute, trough, or pan.
In general electromagnetic powerad vibratory systems are two mass designs each mass carrying either the magnets or the armature. The two masses are connected by springs that normally are sized to have the system utilize resonance amplification of the motion.
Electromagnetics produce useful forces only when the pole faces are in close proximity to each other such as one tenth inch (.1") or less. The attraction force increase approximately with the inverse of the gap squared. The system motion is divided between the two masses inverse to their weight that is, the lighter the mass moves proportionately further. The masses move in opposite directions as the air gap between pole faces increases and decreases.
Provisions must therefore be made to prevent the pole faces from striking as they move close to the minimum gap and magnet force is approaching its peak.
According to an aspect of the invention, in an electromagnetic exciter of the type having a housing capped at opposite longitudinal ends by end caps, the 5~3~
end caps carrying electromagnets inside of the housing, a free mass resiliently supported on the inside of the housing and carrying armature assemblies on opposite longitudinal ends thereof, the end caps further carrying elastomeric compression means spaced apart from the opposite ends of the free mass for preventing armature strike against the electromagnets during electromagnet conduction, an improved elastomeric compression means having a generally semi-circular outer p~riphery,and elongate inner periphery end portions merging the inner and outer peripheries, a planar base surface extending between the end portions, and contour~d contact sur~ace on the opposite side of the base surface extending betw~en the end portions, the contoured surface having a central portion of greater height and thickness than that at the end portions.
According to another asp~ct of the invention, an elastomeric compression element for use in an electromagnetic exciter comprises:
An elastomeric compression ring having a central generally square aperture and having a base surface and a contact surface, the contact surface having rising contoured potions and dipping concave portions alternating around the elastomeric ring, the contoured potions having a height and thickness greater than that of the concave portions.
More particularly, the instant invention provides an electromagnetic vibratory exciter which incorporates a totally enclosed free mass carried inside a elongated housing. The housing includes a pair of end caps each re~eiving a potted electromagnet. The end caps are separated by housing tube secured between them.
The ~ree mass is suspended by elastomeric shear springs inside the housing tube equidistant from each end cap. A pair of armature assemblies are integral ~a~S~3~8 2a with the free mass, one armature at each enc of the generally elongated free mass.
Rubber compression elements are interposed between and normally spaced apart for the free mass and the electromagnetic retaining end caps. These non-linear springs help to avoid armature strike and store the input energy during electromagnetic conduction resulting in high efficiency.
These electromagnets are sequentially energized through a remotely located controller that is connected to the first electromagnetic retaining end cap. An armored _3- ~2S~
c~nduit extends froo the first en~ cap to the 6econ~ en~
cap. Upon energization of the electromagnets in 6equence the free mass will be moved longitudinally through the housing and into contact with the elastomeric compression elements and will cycle back and forth responsive to electromagnet energization and de-energization. The frequency of operation is close to the natural frequency over a broad range of driven weights to utilize resonance.
The apparatus and operation of the invention will be readily understood through a perusal of the following description in conjunction with the drawing figures wherein:
Figure 1 is a simplified illustration of a feeder trough to which the electromagnetic exciter has been mounted;
Figure 2 is an exploded view of the invention with some components bro~;en away;
Figure 3 is an elevation view of Figure 2 with some components broken away and sectioned or clarity;
Figure 4 is an end view of the device of Figure 2 with part of the housing broken away and sectioned;
Figure 5 is a side elevation view of 5-5 of Figure 4.;
. Figure 6 is a graph showing the frequency 2S response range of the electromagnetic exciter;
Figure 7 is a graph showing the energy output of the electromagnet;
Figure 8 is an elevation view of an elastomeric -4- ~5~
com~ression element;
Fiy~re 9 i~ a ~l~n view of ~n elastomeric ring;
Figure 10 is a partially 6ectioned elevation view of the riny of Figure 9 7 A bulk material handliny trough generally 10 in Figure 1 provides a typical application for the electro-magnetic vibratory exciter of the invention. The exciter, generally 12, will be fastened to the trough by means such as fasteners 14. A supply conduit 16 will extend from the electromagnetic exciter to a control module typically remotely stationed.
The mechanical aspects of the invention can be easily understood by studying Figure 2 which is a projected view of the electromaynetic exciter generally 12. The exciter is a uniti~ed closed stLucture having a housing tube 20 which may be of sturdy structural material such as aluminum. Flrst and second end caps 22 and 24 respectivel~, act as magnet housinys each containing a potted electromagnet such as 26 in end cap 24. The end caps 22 and 24 are placed on opposite ends o~ the housing tube 20. In one embodiment studs such as 30 are secured with fasteners such as 32 to securely maintain the housing's integrity. The housing is an elongated container that is sealed against intrusion due to its construction. This containerized housing provides the possibility of an explosion proof housing that -i~ not possible with ~ore conventional electromagnetic exciter6.
The first end cap 22 is provided with an 53~
electrical conduit terminal 2~ to accept the supply con~uit 16. Figure 5 ~hows con~ui~ 34 runniny between the first and ~econd end caps 22 and ?4 for carrying the wire bundle 36 used to provide electrical pulses to the electromagnet 26.
The first end cap 22 may also be provided with threaded apertures s~ch as 40 to provide one method of mountiny the electromagnetic exciter generally 12 to the apparatus to be vibrated.
Looking at Figures 2, 3 and 4, parts solidly carried inside the housing can be identified. Electro-magnet 26, as well as its twin carried at the opposite end of the housing tube 20 ~not visible) and its electrical supply wires from the bundle 36, as well as cover plate 42 are clearly shown.
Inside the housing tube and attached to each end cap are elastomeric compression elements such as pairs of identical elements 4~ and 46 making up spring elements that function as non-linear elements in this system. The pairs differ from each other in the thickness of the elastomeric components~
A first pair 44 of elastomeric compression elements are bonded or otherwise suitably ~ffixed to a - backing plate such as 50 which in ~urn is mounted by 2S fastening means to the inside face of the end plate at e~ch end of the housin~ tube. A cap of fabric reinforced material may be integral with the elastomeric body portion.
The cap would eliminate relative motion between the elas-:~53~ q~
-tomer and the mounting pla-te 76 during spring compression.
The second pair ~6 of the elastomeric compression elements 46 are also suitably affixed to a similar backing plate but may have shims, one shown as 52, interposed between -the backing plate and the end cap to which it is mounted.
The elastomeric compression elemen-ts are symmetrically arranged so that pair members are on diame-trically opposi-te sides of the longitudinal axis of the diametrically opposite sides of the longituclinal axis of the housing. The thickness of the elastomeric compression elements and the shims associated therewith are variables that can be changed in order to provlde desirable operating characteris-tics of a specified electromagnetic exciter. The stacking height of each pair of elastomeric compression elements at each end of the housing may be different from the other pair at the same end so that better control of the non-linear aspect of this spring means is possible. The elastomeric compression elements provide a non-linear stiffening rate and self-limiting deflection of the device.
The elastomeric compression elements such as ~6 can be fabricated with a crowned surface such that the thickness of the elastomeric compression element is not uniform throughout its relative length. E'igure 8 shows an elastomeric compression element 100 affixed -to backing pla-te 50, which has a crowned portion 102 that may be an exaggeration of -the degree of the crown portion but is representative of the concept. Multiple crowns and concave portions are possibilities contemplated by -the inventors as is a "stepped embodiment"
~5 ~ 3~ ~
w~ere there would be more radical demarcations between the thicker and thinner portions of the elastomerlc c~mpression element.
Alternative em~odiments may include fewer than or 5 more than the four elements shown in the presentation of the preferred embodiment. Other embodiments of elastomeric compression elements are also contemplated by the inventor. For instance, Figure 9 shows a single elastomeric compression element 104 that is basically an elastomeric ring with a central aperture such as 106, that may be of a shape other than that as shown as long as it accommodates the armature B0 which could also be of a shape other than the ser.erally rectansular shape as depicted in the drawings. The elastomeric ring could be suitably affixed to bac~ing plates such as 50, for example, or could be attached to a unitary backing plate such as 108. The backing plate is optional as the ring 104 could ~e attached directly to the interior of the end caps or to the mounting plate 76.
Figure 10 shows a partially sectioned embodiment in side elevation view of Figure 9 with a crowned portion shown as 110 and different height crown portions such as 112. The top surface could be of many configurations including a flat surface, a wave form surface with crowns and concave section6 of various dimensions alternating around the ring or a ~tepped~ surface o variou~ height~
~lternating aroung the ring. Figure 10 i~ not pre6ented as a limiting feature but i exemplary of the undulating ~53~8~
surface ~ossibiliti~s contem~lated by the inventors.
cap of ~abric reinforced material may also be integral with these embodiment~ of elastomeric rinys.
It should be noted that the housing tube and end ca~s as well as all the equipment and parts mentioned - above are part of the dr iven mass in the vibrating system since they are integrally connected together in the assemblie~ embodiment.
A free mass generally 60 is totally enclosed and suspended inside the housing tube 20 between the end caps 22 and 24. Figure.s 2 and 3 are helpful in identifying its parts. First and second shear springs 54 and 56 are pressed into the interior of the elonyated housing tube 20 to suspend the free mass generally 60.
The free mass includes a central member 62 of a generally elongate configuration having apertured wall portions defining a pair of recesses such as 64. This free mass is supported by and functionally secured to the inside apertures of the first and second shear springs.
Retainer means such as threaded rod 66 is provided to retain tuning weights such as 70 which may be held in place by fasteners.
The tuning weights such as 70 are important to . 7 this invention as they are an interchangeable element that enables changes in the weight of the free ma~s even though the general fiizes and component configuration of the electromagnetic exciter remains constant. Tuning weight6 can be changed without the need of changing or adjusting ~3~
the rate o~ the supporting sprinys during tuning. Thus exciters of different capacities can be manufactured from common compollents to advantageously utilize economies of ~cale. ~niver~al tunin~ is made possible by the proper selection of the natural frequency of the free mass and the springs 54 and 56. This universal tuniny allows the exciter to delaver rated power regardless of the weight of the driven member to which it is attached.
After the tuning weights are in position the flange plates such as 72 are suitably fastened to the opposite ends of the central member 62. Armature assemblies generally 74, including a mounting plate 76 and a generally rectangular armature ~0 are fastened to the flange plate 72. An alternative method of assembly would be to eli~inate the mounting plates and mount the armatures directly to the flange plates 720 Upon assembly of the electromagnetic exciter an air gap 82 exists between the face o~ the armatures such as 80 and the faces of the electromagnets such as 26 when in a static state. ~pon actuation the air gap will cyclically decrease and increase but the pole faces will not strike if proper spring selection has been made.
It should be mentioned, as is obvious from the ~ drAwing figures, that components on the interior of the hou6ing are symetrically similar on each end of the central member. The 6ymme~ry resul~ing from thi6 ~tructure and the dual opposing electromagnets i6 bene-~icial to yood exciter operation. Figures 6 and 7 graph-~3~
ically dis~lay the a~vantages gained through the em~odi-ment presented herein.
Figure 6 graphically represents the universal tuning advantage of the exciter. The frequency ratio on the x-axis shows that maximum amplitude occurs where the operating frequency of the exciter and the natural frequency of the system are the same. The included portion of the curve between A and ~ represents the operating region for an exciter of a given free mass applied to a broad range of driven weiyhts. The exciter is tune~; by judicious selector of the tuning weights, such that the natural frequency of the system is equal to the operatiny frequency of the exciter. That would mean that the exciter would be tuned so that the frequency ration is between A an~ B Eor a broad range of driven weiyhts. .he resonance amplification in this range is at least five.
The exciter would continue to perform efficiently to super-resonance represented where line B .intersects the curve. The resonance amplification factor would again be five. In summary it is ap~arent that this exciter is close to resonance over a broad weight range of driven masses.
- Without the compression elements the pole faces would strike at the higher amplification factor~. Line C
shows the full ~ystem deflection which i~ maint~ined by these element6.
In Figure 7 the electrical power pul~e timiny ~nd ~ S~3~ ~ ~
the force produced by the electromagnet is graphically depicted. Each electromagnet is energized once per mechanical cycle. Although not shown in the drawing fiyures a controller will be remotely mounted from the exciter and designed to supply each electromagnet sequen-tially with a pulse of electrical eneryy timed appropri-ately to energize each electromagnet. The static air gap A at the right side of the graph depicts a position where the armature free mass is equally spaced apart from the electromagnets. Proceeding to the left of the graph towards the minimum air gap the duration of the electrical pulse to the electromagnet is shown by the c~rve designated as broken line C. The force produced by the electromagnet is shown by curve D while the area under the curve is the energy output of the magnetO The electro-ma~net is energized during the deflection of the free mass towards the electromagnets in the zone from E to B (the minimum air gap). As the air yap opens current continues to flow back to point F therefore the net energy produced is that indicated by the crosshatched area under the curve.
This energy is that stored in the compression springs 44 and 46. ~lectromagnet coils designed for energiæation in the manner described make it possible to store ~ignifi-cantly more energy per cycle then the designs of the prior art.
Dependiny on the design of the compres~ion element~ this ~tored energy re6ulting from the initial impact of the free mass directed toward the compression ~25~ 3 element provides approximately 3D~ of the force neede~ to accelerate the ~ree mass in the opposite direction. ~his results in an electriGal power ~avings and the attendan~
cost benefit. Since the compression elements ~re non-5 linear any armature strikins can be avoided through properselection of the elements.
The invention concerns electromagnetic vibratory exciters for use in imparting vibratory excitation into a host mass for use, for instancel in vibratory conveyor equipment bin hoppers and chutes for bulk material transport and metered delivery.
Electromagnetic vibratory drive units have been extensively used in industry to ensure the smooth flow of bulk material from storage bins, hoppers and delivery chutes. Electromagnetic vibratory drive units are also used in vibratory feeders for feeding various bulk materials to mixers, grinders, crushers, packaging machinery, batching, grading or mixing stations. The electromagnetic exciters are coupled to a delivery trough which is vibrated by the exciter to control material flow along the chute, trough, or pan.
In general electromagnetic powerad vibratory systems are two mass designs each mass carrying either the magnets or the armature. The two masses are connected by springs that normally are sized to have the system utilize resonance amplification of the motion.
Electromagnetics produce useful forces only when the pole faces are in close proximity to each other such as one tenth inch (.1") or less. The attraction force increase approximately with the inverse of the gap squared. The system motion is divided between the two masses inverse to their weight that is, the lighter the mass moves proportionately further. The masses move in opposite directions as the air gap between pole faces increases and decreases.
Provisions must therefore be made to prevent the pole faces from striking as they move close to the minimum gap and magnet force is approaching its peak.
According to an aspect of the invention, in an electromagnetic exciter of the type having a housing capped at opposite longitudinal ends by end caps, the 5~3~
end caps carrying electromagnets inside of the housing, a free mass resiliently supported on the inside of the housing and carrying armature assemblies on opposite longitudinal ends thereof, the end caps further carrying elastomeric compression means spaced apart from the opposite ends of the free mass for preventing armature strike against the electromagnets during electromagnet conduction, an improved elastomeric compression means having a generally semi-circular outer p~riphery,and elongate inner periphery end portions merging the inner and outer peripheries, a planar base surface extending between the end portions, and contour~d contact sur~ace on the opposite side of the base surface extending betw~en the end portions, the contoured surface having a central portion of greater height and thickness than that at the end portions.
According to another asp~ct of the invention, an elastomeric compression element for use in an electromagnetic exciter comprises:
An elastomeric compression ring having a central generally square aperture and having a base surface and a contact surface, the contact surface having rising contoured potions and dipping concave portions alternating around the elastomeric ring, the contoured potions having a height and thickness greater than that of the concave portions.
More particularly, the instant invention provides an electromagnetic vibratory exciter which incorporates a totally enclosed free mass carried inside a elongated housing. The housing includes a pair of end caps each re~eiving a potted electromagnet. The end caps are separated by housing tube secured between them.
The ~ree mass is suspended by elastomeric shear springs inside the housing tube equidistant from each end cap. A pair of armature assemblies are integral ~a~S~3~8 2a with the free mass, one armature at each enc of the generally elongated free mass.
Rubber compression elements are interposed between and normally spaced apart for the free mass and the electromagnetic retaining end caps. These non-linear springs help to avoid armature strike and store the input energy during electromagnetic conduction resulting in high efficiency.
These electromagnets are sequentially energized through a remotely located controller that is connected to the first electromagnetic retaining end cap. An armored _3- ~2S~
c~nduit extends froo the first en~ cap to the 6econ~ en~
cap. Upon energization of the electromagnets in 6equence the free mass will be moved longitudinally through the housing and into contact with the elastomeric compression elements and will cycle back and forth responsive to electromagnet energization and de-energization. The frequency of operation is close to the natural frequency over a broad range of driven weights to utilize resonance.
The apparatus and operation of the invention will be readily understood through a perusal of the following description in conjunction with the drawing figures wherein:
Figure 1 is a simplified illustration of a feeder trough to which the electromagnetic exciter has been mounted;
Figure 2 is an exploded view of the invention with some components bro~;en away;
Figure 3 is an elevation view of Figure 2 with some components broken away and sectioned or clarity;
Figure 4 is an end view of the device of Figure 2 with part of the housing broken away and sectioned;
Figure 5 is a side elevation view of 5-5 of Figure 4.;
. Figure 6 is a graph showing the frequency 2S response range of the electromagnetic exciter;
Figure 7 is a graph showing the energy output of the electromagnet;
Figure 8 is an elevation view of an elastomeric -4- ~5~
com~ression element;
Fiy~re 9 i~ a ~l~n view of ~n elastomeric ring;
Figure 10 is a partially 6ectioned elevation view of the riny of Figure 9 7 A bulk material handliny trough generally 10 in Figure 1 provides a typical application for the electro-magnetic vibratory exciter of the invention. The exciter, generally 12, will be fastened to the trough by means such as fasteners 14. A supply conduit 16 will extend from the electromagnetic exciter to a control module typically remotely stationed.
The mechanical aspects of the invention can be easily understood by studying Figure 2 which is a projected view of the electromaynetic exciter generally 12. The exciter is a uniti~ed closed stLucture having a housing tube 20 which may be of sturdy structural material such as aluminum. Flrst and second end caps 22 and 24 respectivel~, act as magnet housinys each containing a potted electromagnet such as 26 in end cap 24. The end caps 22 and 24 are placed on opposite ends o~ the housing tube 20. In one embodiment studs such as 30 are secured with fasteners such as 32 to securely maintain the housing's integrity. The housing is an elongated container that is sealed against intrusion due to its construction. This containerized housing provides the possibility of an explosion proof housing that -i~ not possible with ~ore conventional electromagnetic exciter6.
The first end cap 22 is provided with an 53~
electrical conduit terminal 2~ to accept the supply con~uit 16. Figure 5 ~hows con~ui~ 34 runniny between the first and ~econd end caps 22 and ?4 for carrying the wire bundle 36 used to provide electrical pulses to the electromagnet 26.
The first end cap 22 may also be provided with threaded apertures s~ch as 40 to provide one method of mountiny the electromagnetic exciter generally 12 to the apparatus to be vibrated.
Looking at Figures 2, 3 and 4, parts solidly carried inside the housing can be identified. Electro-magnet 26, as well as its twin carried at the opposite end of the housing tube 20 ~not visible) and its electrical supply wires from the bundle 36, as well as cover plate 42 are clearly shown.
Inside the housing tube and attached to each end cap are elastomeric compression elements such as pairs of identical elements 4~ and 46 making up spring elements that function as non-linear elements in this system. The pairs differ from each other in the thickness of the elastomeric components~
A first pair 44 of elastomeric compression elements are bonded or otherwise suitably ~ffixed to a - backing plate such as 50 which in ~urn is mounted by 2S fastening means to the inside face of the end plate at e~ch end of the housin~ tube. A cap of fabric reinforced material may be integral with the elastomeric body portion.
The cap would eliminate relative motion between the elas-:~53~ q~
-tomer and the mounting pla-te 76 during spring compression.
The second pair ~6 of the elastomeric compression elements 46 are also suitably affixed to a similar backing plate but may have shims, one shown as 52, interposed between -the backing plate and the end cap to which it is mounted.
The elastomeric compression elemen-ts are symmetrically arranged so that pair members are on diame-trically opposi-te sides of the longitudinal axis of the diametrically opposite sides of the longituclinal axis of the housing. The thickness of the elastomeric compression elements and the shims associated therewith are variables that can be changed in order to provlde desirable operating characteris-tics of a specified electromagnetic exciter. The stacking height of each pair of elastomeric compression elements at each end of the housing may be different from the other pair at the same end so that better control of the non-linear aspect of this spring means is possible. The elastomeric compression elements provide a non-linear stiffening rate and self-limiting deflection of the device.
The elastomeric compression elements such as ~6 can be fabricated with a crowned surface such that the thickness of the elastomeric compression element is not uniform throughout its relative length. E'igure 8 shows an elastomeric compression element 100 affixed -to backing pla-te 50, which has a crowned portion 102 that may be an exaggeration of -the degree of the crown portion but is representative of the concept. Multiple crowns and concave portions are possibilities contemplated by -the inventors as is a "stepped embodiment"
~5 ~ 3~ ~
w~ere there would be more radical demarcations between the thicker and thinner portions of the elastomerlc c~mpression element.
Alternative em~odiments may include fewer than or 5 more than the four elements shown in the presentation of the preferred embodiment. Other embodiments of elastomeric compression elements are also contemplated by the inventor. For instance, Figure 9 shows a single elastomeric compression element 104 that is basically an elastomeric ring with a central aperture such as 106, that may be of a shape other than that as shown as long as it accommodates the armature B0 which could also be of a shape other than the ser.erally rectansular shape as depicted in the drawings. The elastomeric ring could be suitably affixed to bac~ing plates such as 50, for example, or could be attached to a unitary backing plate such as 108. The backing plate is optional as the ring 104 could ~e attached directly to the interior of the end caps or to the mounting plate 76.
Figure 10 shows a partially sectioned embodiment in side elevation view of Figure 9 with a crowned portion shown as 110 and different height crown portions such as 112. The top surface could be of many configurations including a flat surface, a wave form surface with crowns and concave section6 of various dimensions alternating around the ring or a ~tepped~ surface o variou~ height~
~lternating aroung the ring. Figure 10 i~ not pre6ented as a limiting feature but i exemplary of the undulating ~53~8~
surface ~ossibiliti~s contem~lated by the inventors.
cap of ~abric reinforced material may also be integral with these embodiment~ of elastomeric rinys.
It should be noted that the housing tube and end ca~s as well as all the equipment and parts mentioned - above are part of the dr iven mass in the vibrating system since they are integrally connected together in the assemblie~ embodiment.
A free mass generally 60 is totally enclosed and suspended inside the housing tube 20 between the end caps 22 and 24. Figure.s 2 and 3 are helpful in identifying its parts. First and second shear springs 54 and 56 are pressed into the interior of the elonyated housing tube 20 to suspend the free mass generally 60.
The free mass includes a central member 62 of a generally elongate configuration having apertured wall portions defining a pair of recesses such as 64. This free mass is supported by and functionally secured to the inside apertures of the first and second shear springs.
Retainer means such as threaded rod 66 is provided to retain tuning weights such as 70 which may be held in place by fasteners.
The tuning weights such as 70 are important to . 7 this invention as they are an interchangeable element that enables changes in the weight of the free ma~s even though the general fiizes and component configuration of the electromagnetic exciter remains constant. Tuning weight6 can be changed without the need of changing or adjusting ~3~
the rate o~ the supporting sprinys during tuning. Thus exciters of different capacities can be manufactured from common compollents to advantageously utilize economies of ~cale. ~niver~al tunin~ is made possible by the proper selection of the natural frequency of the free mass and the springs 54 and 56. This universal tuniny allows the exciter to delaver rated power regardless of the weight of the driven member to which it is attached.
After the tuning weights are in position the flange plates such as 72 are suitably fastened to the opposite ends of the central member 62. Armature assemblies generally 74, including a mounting plate 76 and a generally rectangular armature ~0 are fastened to the flange plate 72. An alternative method of assembly would be to eli~inate the mounting plates and mount the armatures directly to the flange plates 720 Upon assembly of the electromagnetic exciter an air gap 82 exists between the face o~ the armatures such as 80 and the faces of the electromagnets such as 26 when in a static state. ~pon actuation the air gap will cyclically decrease and increase but the pole faces will not strike if proper spring selection has been made.
It should be mentioned, as is obvious from the ~ drAwing figures, that components on the interior of the hou6ing are symetrically similar on each end of the central member. The 6ymme~ry resul~ing from thi6 ~tructure and the dual opposing electromagnets i6 bene-~icial to yood exciter operation. Figures 6 and 7 graph-~3~
ically dis~lay the a~vantages gained through the em~odi-ment presented herein.
Figure 6 graphically represents the universal tuning advantage of the exciter. The frequency ratio on the x-axis shows that maximum amplitude occurs where the operating frequency of the exciter and the natural frequency of the system are the same. The included portion of the curve between A and ~ represents the operating region for an exciter of a given free mass applied to a broad range of driven weiyhts. The exciter is tune~; by judicious selector of the tuning weights, such that the natural frequency of the system is equal to the operatiny frequency of the exciter. That would mean that the exciter would be tuned so that the frequency ration is between A an~ B Eor a broad range of driven weiyhts. .he resonance amplification in this range is at least five.
The exciter would continue to perform efficiently to super-resonance represented where line B .intersects the curve. The resonance amplification factor would again be five. In summary it is ap~arent that this exciter is close to resonance over a broad weight range of driven masses.
- Without the compression elements the pole faces would strike at the higher amplification factor~. Line C
shows the full ~ystem deflection which i~ maint~ined by these element6.
In Figure 7 the electrical power pul~e timiny ~nd ~ S~3~ ~ ~
the force produced by the electromagnet is graphically depicted. Each electromagnet is energized once per mechanical cycle. Although not shown in the drawing fiyures a controller will be remotely mounted from the exciter and designed to supply each electromagnet sequen-tially with a pulse of electrical eneryy timed appropri-ately to energize each electromagnet. The static air gap A at the right side of the graph depicts a position where the armature free mass is equally spaced apart from the electromagnets. Proceeding to the left of the graph towards the minimum air gap the duration of the electrical pulse to the electromagnet is shown by the c~rve designated as broken line C. The force produced by the electromagnet is shown by curve D while the area under the curve is the energy output of the magnetO The electro-ma~net is energized during the deflection of the free mass towards the electromagnets in the zone from E to B (the minimum air gap). As the air yap opens current continues to flow back to point F therefore the net energy produced is that indicated by the crosshatched area under the curve.
This energy is that stored in the compression springs 44 and 46. ~lectromagnet coils designed for energiæation in the manner described make it possible to store ~ignifi-cantly more energy per cycle then the designs of the prior art.
Dependiny on the design of the compres~ion element~ this ~tored energy re6ulting from the initial impact of the free mass directed toward the compression ~25~ 3 element provides approximately 3D~ of the force neede~ to accelerate the ~ree mass in the opposite direction. ~his results in an electriGal power ~avings and the attendan~
cost benefit. Since the compression elements ~re non-5 linear any armature strikins can be avoided through properselection of the elements.
Claims (10)
- I. In an electromagnetic exciter of the type having a housing capped at opposite longitudinal ends by end caps, the end caps carrying electromagnets inside of the housing, a free mass resiliently supported on the inside of the housing and carrying armature assemblies on opposite longitudinal ends thereof, the end caps further carrying elastomeric compression means spaced apart from the opposite ends of the free mass for preventing armature strike against the electromagnets during electromagnet conduction, an improved elastomeric compression means having a generally semi-circular outer periphery,and elongate inner periphery end portions merging the inner and outer peripheries, a planar base surface extending between the end portions, and a contoured contact surface on the opposite side of the base surface extending between the end portions, the contoured surface having a central portion of greater height and thickness than that at the end portions.
- 2. The invention an accordance with claim 1, wherein the planar base surface is bonded to a backing plate means for use in mounting the elastomeric compression means to the end caps. I
- 3. The invention in accordance with claim 1, wherein there are two pairs of diametrically opposite elastomeric compression means for mounting to the end caps forming a segmented ring.
- 4. The invention in accordance with claim 3, wherein one pair of elastomeric compression means is of lesser height than the other pair.
- 5. The invention in accordance with claim 4, wherein both pairs of elastomeric compression means are bonded to backing plate means for use in mounting the elastomeric compression means to the end caps.
- 6. The invention in accordance with claim 2, wherein a shim is provided between the backing plate and end cap for spacing the one pair of elastomeric compression means a predetermined distance from the end of the free mass.
- 7. The invention in accordance with claim 2, wherein a shim is provided between the backing plate and end cap for spacing the elastomeric compression means a predetermined distance from the end of the free mass.
- 8. An elastomeric compression element for use in an electromagnetic exciter comprising:
an elastomeric ring having a central generally square aperture and having a base surface and a contact surface, the contact surface having rising contoured portions and dipping concave portions alternating around the elastomeric ring, the contoured portions having a height and thickness greater than that of the concave portions. - 9. The invention in accordance with claim 8, wherein the base surface of the elastomeric ring is affixed to a unitary backing plate.
- 10. The invention in accordance with claim 9, wherein the contoured portions have varying heights and the concave portions have varying depths.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US58772484A | 1984-03-08 | 1984-03-08 | |
| US587,724 | 1984-03-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1253189A true CA1253189A (en) | 1989-04-25 |
Family
ID=24350948
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000475920A Expired CA1253189A (en) | 1984-03-08 | 1985-03-07 | Electromagnetic vibratory exciter |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS60209422A (en) |
| AU (1) | AU576543B2 (en) |
| BR (1) | BR8501019A (en) |
| CA (1) | CA1253189A (en) |
| DE (1) | DE3508367A1 (en) |
| ES (1) | ES8603298A1 (en) |
| FR (1) | FR2563125B1 (en) |
| GB (1) | GB2155701B (en) |
| ZA (1) | ZA851764B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5287027A (en) * | 1991-11-01 | 1994-02-15 | Fmc Corporation | Electromagnetic drive for use with vibratory conveyors |
| US5293987A (en) * | 1992-02-21 | 1994-03-15 | Fmc Corporation | Feeder drive |
| KR102130441B1 (en) * | 2017-10-30 | 2020-07-07 | 주식회사 이엠텍 | Actuator having a elastic injection molded frame |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE884120C (en) * | 1950-12-15 | 1953-07-23 | Licentia Gmbh | Tuned electromagnetic vibrating motor with progressive suspension |
| GB887473A (en) * | 1958-01-24 | 1962-01-17 | Cie Parisienne Outil Air Compr | Improvements in or relating to jacks |
| GB1293248A (en) * | 1970-03-12 | 1972-10-18 | Barkas Werke Veb | Improvements in or relating to resilient bodies especially for use as spring members in motor vehicles |
| US3913460A (en) * | 1972-08-10 | 1975-10-21 | Mosier Ind Inc | Impact damping means for fluid cylinders |
| JPS5123797B2 (en) * | 1973-12-28 | 1976-07-19 | ||
| GB1448548A (en) * | 1974-01-15 | 1976-09-08 | Mosier Ind Inc | Impact damping means for fluid actuators |
| US3932005A (en) * | 1974-05-10 | 1976-01-13 | Uniroyal Inc. | Elastomeric railway car with side bearing |
| DE7417627U (en) * | 1974-05-21 | 1974-10-03 | Imexin Sa Nv | Vibration damper |
| GB1539869A (en) * | 1977-08-01 | 1979-02-07 | Chane Mfg Co Ltd H | Vibratory motor assembly |
| IL59740A0 (en) * | 1980-03-31 | 1980-06-30 | Popper Eng Ltd | Electromagnetic vibrating system operable at high amplitudes |
| US4455496A (en) * | 1982-02-25 | 1984-06-19 | Fmc Corporation | Electromagnetic vibratory exciter |
| US4673833A (en) * | 1982-02-25 | 1987-06-16 | Fmc Corporation | Electromagnetic vibratory exciter |
| US4550266A (en) * | 1984-01-21 | 1985-10-29 | J. Wagner Gmbh | Reciprocating armature motor for driving electrical equipment |
-
1985
- 1985-02-27 AU AU39218/85A patent/AU576543B2/en not_active Ceased
- 1985-03-06 GB GB08505711A patent/GB2155701B/en not_active Expired
- 1985-03-07 JP JP60043858A patent/JPS60209422A/en active Granted
- 1985-03-07 BR BR8501019A patent/BR8501019A/en not_active IP Right Cessation
- 1985-03-07 CA CA000475920A patent/CA1253189A/en not_active Expired
- 1985-03-08 DE DE19853508367 patent/DE3508367A1/en active Granted
- 1985-03-08 ZA ZA851764A patent/ZA851764B/en unknown
- 1985-03-08 FR FR858503453A patent/FR2563125B1/en not_active Expired - Lifetime
- 1985-03-08 ES ES541104A patent/ES8603298A1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| AU3921885A (en) | 1985-09-12 |
| DE3508367A1 (en) | 1985-09-12 |
| FR2563125A1 (en) | 1985-10-25 |
| ZA851764B (en) | 1985-11-27 |
| ES541104A0 (en) | 1985-12-16 |
| GB2155701B (en) | 1987-09-23 |
| BR8501019A (en) | 1985-10-29 |
| DE3508367C2 (en) | 1991-05-16 |
| JPS60209422A (en) | 1985-10-22 |
| GB8505711D0 (en) | 1985-04-11 |
| FR2563125B1 (en) | 1991-08-16 |
| ES8603298A1 (en) | 1985-12-16 |
| JPH0353211B2 (en) | 1991-08-14 |
| AU576543B2 (en) | 1988-09-01 |
| GB2155701A (en) | 1985-09-25 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |