DE1613452A1 - Electromagnetic reversing actuator - Google Patents

Description

Patent attorneys Dipl.-Ing. EWeickmann, Dr. Ing.A.Weickmann

Dipl.-Ing. H.Weickmann, Dipl ^ -Phys. Dr. K. Fincke Dipl ^ -Ing. F. A-Weickmann, Dipl.-Chem. B. Huber

8 MUNICH 27, DEN

MÖHLSTRASSE 22, CALL NUMBER 48 3921/22

USIIED AIRGlUE [D CORPORATION, 400 Hain Street, Sa Hartford, Connecticut (inj ^ in Delaware}, U.S.A.

Slelcbromagne ti seller Uüifcehr actuator "

The invention "relates sicii generally to an electromagnet iscnen actuator and in particular on an act of reversal uat or for driving a back and forth. forward part, e.g. a pump or the like *

With. "The advent of the heart pump systeria resulted in you There is a need for an electromagnetic actuator that moves the plunger back and forth it depends on both the speed and the Stroke length of the pump, accurate in both directions of movement, to control. The actuator according to the invention is not

limited to the use for the xaittrieb doe back and hergeilenden piston of a Herapunpe, but can also used in other closed Ilegelochleifensysteuen find where it is necessary to precisely control the piston stroke in such pumps. liie use however, a fluid pump is a particularly suitable example.

A heart pump includes a reciprocating piston, which forms a blood pumping chamber in a surrounding cylinder. Catheters are connected to the blood pumping chamber connected to the patient's circulatory system to support the circulatory system. The speed of movement of the heart pump piston varies during the flow, for coincidence between a cyclic signal (2KG-3ignul), which represents one of the physiological parameters of the patient, and every pump cycle (a reciprocation of the pump piston). Furthermore, the blood volume, which is pumped per cycle, controlled by changing the stroke length of the piston. When using the .ictuators according to the invention for actuating a heart pump one uses to control both the stroke frequency and the stroke length of the pump piston in accordance with certain circulatory processes of a computer control system. It is clear that here it is both from The point of view of avoiding hemolysis as well as achieving adequate perfusion is important,

8 33/0474 bad

that the movement of the umpenkoll> enß is precisely controlled \ ιηά according to the. given by the associated computer Kbmmandodat en takes place, "...- ■

The invention has the object 'based on i a solenoid ie chen: 0nucehraktuator to provide ,, the, di exerts on eiiaen micro and disappearing anchor a force; e is a linear function of the Ankerstrümes ;. The power output should be approximately constant over the entire stroke of the deeinker with a constant current. : ^.

The according to the invention electromagnetic; Omkehrau & he is characterized by -by; two sows of rin ^ fSraig'- arranged. , Drove windings which constant current in the opposite direction, '^ Lamelleii separating the viickluticen and against each column having, "ad durcli within the windings a back and he bewegliehe ν n is constant magnetic; Jöiicer excited with end pieces' whose .Each-^ lies within the axial iaiige of the windings and laminations and relatively sur axial Lilnge the plurality vöjl windings and the iaaeliea ßine! deine-., However, relatively au Each iamelle and jedeiä a gap Grose ^ axial Length possesses ^ so that one is the ^ iclcluiigeia. a SiGlitpng through flieüenlör Stros a ¹ in the v / eseirrlielien iConstante. ■■ Terschiebglifaft in a Eiebtung and, upon reversal of the current eine.konstante pushing force "in entgegengesetsT ter calibration Tung on the ^ iker _{exerts;; ':}

BADGRK3JNAL

As mentioned, the reversing anchor according to the invention is used in the ■ special for operating a heart pump that has a reciprocating, double * acting piston, one cylinder chamber of which is connected to a catheter to be introduced into the circulatory system of the patient other cylinder chamber communicates with a chamber of a cylinder in which one of the actuator shaft driven "piston is guided, the two chambers connected by a fluid coupling are so that the movements of the piston of the actuator transferred to the piston of the "heart pump *

The figures explain the invention using an exemplary embodiment. They represent:

1 shows the device in elevation, partially in section, the electromagnetic actuator driving a reciprocating heart pump,
Fig. 2 to 4 the inventive electromagnetic

Actuator, with the armature shown in different • positions of its stroke, Fig. 5 is a diagram of the relationship between the armature 'current and the armature force over the length of the armature stroke »

The actuator according to the invention can be embodied in different forms and used for different Zv / corners will. The example shown is the application

for operating a reciprocating heart pump. ■ "■ · ■" ■ ■■■■ - ■■ · "'■■ * ■■■

".9-833 / (K? 4

At Eig. 1 is a pump 10 that generates pressure in time with the pulse. This pump consists of a cylindrical housing 1Ϊ. with a cylinder 12 in which a double-acting piston 14 moves back and forth "The basket 14" defines a blood pumping chamber 16 at the front end of the cylinder 12 and an actuating chamber 36 at the other end. A catheter arrangement 20 is connected to the blood pumping chamber 16 to generate an arterio-arterial pumping action (ie a circulation that technically supports the circulation). Catheters 22 and 23 are inserted into the patient's ffemoral arteries and pushed close up into the descending aorta. As the piston 14 reciprocates in the cylinder 12, blood or other fluid is forced through the catheter assembly 20 in the patient's aorta and "causes the intric-aortic pressure to increase in time with the patient's EXi &" waveform * This Stüirstmg causes the peripheral ?! flow (Perf USLON) "Wircü ü®v piston 14 sound his left Satpunkt in the gylijuier IZ ~ m is. blood tone äem 3 £ a-theter in the JDamsiOT 16 · wherein the arterial resistance, geg <m veleliea the a @ s? s puiEpsn iOFF _f verriugert viird. the

; _t Sin xuLphtgeaeiobnator Soilwater, äa $ in Abfe ^ a ^ igfeeit rcn ■ $ er HesiS3yi ^ lU0pe3 * iode ties BatieÄfeafö o & ex? tux) Mo ! .the PElsfrs ^ ueixs work- _s © rr © Clipart 5öi9t »qwöSü, die;

l · digkelt dfl "» Ein, · »PX ^ SestittviigissjK de ^ Kolbejsi» 14 · * -? 4e suoh

the stroke length of the piston to maintain a maximum Flow without causing hemolysis. According to the present invention is used for the actuation of the back and the reciprocating piston of the heart pump, an electromagnetic actuator 25, which controls the piston 14 via a liquid clutch drives in such a way that the pump 14 can be set up away from the actuator 25.

The fluid coupling 27 consists of a cylinder 29 which is attached to the electromagnetic actuator 25 and forms a cylinder 30 for a piston 32. The piston 32 defines a fluid chamber 35 in the cylinder 30 which communicates with the chamber 36 in the pump 10 through a flexible hose 38. The pump 27 is a "rigid ¹¹ ! Fluid coupling in the sense that the piston 14 exactly follows the movement of the piston 32. A feedback potentiometer 40 is connected to the piston 32 and gives a signal to a closed control loop in the Reohensobaltung, which is the instantaneous Indicates position of the piston 14 at any moment during the stroke of the same.

The electromagnetic actuator 25 has a non-magnetic check cylindrical housing member 42 with fastened thereon. end plates 43 and 44, which are also non-magnetic.

In the Oti & äi? Tfe 4 ^ Ijeiir.äet »eich an Asker 47» 4er enlarged sylißdrlaohe Bndetüofce 49 and 50, connected

duroh a rope 51 3cle.iKi.eren Xüurehmeeser ·, wliet.

009833/0474

The armature 47 is rigidly connected, so that the armature reciprocates the piston having a shaft 53 which is in turn ^x rigidly connected to the piston 32 back and forth. The armature 47 does not have any turns, so that it has little inertia and responds quickly »

An annular permanent I-magnet 55 is in the housing 42 is arranged centrally and provides the excitation field for the armature 47. Alternatively, an electromagnet can also are used either instead of the magnet 55 or in addition to this. However, the 4 permanent magnet 55 has two advantages over electric field excitation: he does not need a supplied service and he holds the 3? eid intensity in the magnetic circuit constant due to less reversible permeability. On both sides des Ilagneten 55 is a plurality of annular Armature windings 53 are provided. The armature windings 53 are in two sets 65A and 65B on opposite one another Sides of the magnet 55 arranged; they are so with each other connected that when the current is in one direction

"."; .. flows in the set 65A, runs the calibration Tung in the Sata 65B in the other direction. The armature winding is powered by an Ereis, which the

: Direction of movement in each set of turns reverses to

ί ■ to move the armature 47 back and forth, and the control data

(;, of the computer converted into a predetermined current level.

^: '■ ORIGINALINSPECTED

; 3λΤΑ ~ m: h ?:>;H; -i 009 8 3 3 .. ""

Annular lamellae 60 separate the individual windings 58 and form flow paths with the pieces 49 and These lamellae have enlarged inner parts 61 which reduce the gap 62 between the lamellae and thereby contribute to increasing the linearity of the actuator.

The linearity of the actuator 25 is mainly due by the ratio between the axial length of the end pieces 49 and 50 in relation to the enlarged inner parts 61 of the laminations, the gaps 62 and the length of the winding sets 65A and 65B. A constant Driving current in the windings 58 causes a uniform Kraft for the displacement of the anchor 47 thanks the constant number of flight connections with the armature, i.e. the reluctance of the magnetic circuit is essentially constant over the stroke length of the armature 47 »since the end pieces 49 and 50 in relation to the end parts 61 of the Lamellae 60 have such an axial length that a substantially constant lamellae area in all positions of the armature 47 next to the end pieces is present .. In the Embodiment of fig. 1 each end piece has an axial Length which is substantially equal to the sum of the axial lengths of two lamella parts 61 and two columns 62. Furthermore, the length of each set of windings 65A and 65B (including the laminations) is considerably greater than the axial length of each of the end pieces 49 and 50 to reduce the non-linearity caused by edge impact to reduce. The length 65 is in the example

* Twice as large as the axial length of each of the end pieces

009833/0474

Additionally, the end pieces 4-9 and 50 are opposite the Gaps 62 between the slats relatively wide, to reduce the impact of these gaps on linearity.

An annular compensation winding 70 can be provided be to overcome the anchor reaction by generating a magnetomotive force in a direction opposite to the demagnetizing magnetomotive force Force of anchor reaction. The power supply to winding 70 is intended to vary with stroke or displacement the anchor reaction associated with the. Stroke varies, to compensate.

The mode of operation is described with reference to FIGS. 2 to Φ, in which an electromagnetic actuator is shown i which differs somewhat from that of FIG an electromagnet 75 is generated. The field magnet 75 is supplied with current which flows continuously in the same direction regardless of the stroke direction of the armature 47. The current flow is in the Pig. 2 to 4 · indicated by black dots. The field magnets 55 and 75 work together to generate a magnetic field or flux B. If no current flows in the windings .58 (Fig. 2), then no movement of the armature 4-7 is generated ν

009 83 3/0474 ^/

the current flows in the black windings of the jig. 3, then the anchor moves 4-7 to the left. The movement of the armature can be explained in simplified form as follows: The constant field excitation by the permanent magnet and the electromagnet 75 has the effect that the end piece 49 becomes the south pole and the end piece 50 becomes the north pole. The polarity of the end pieces 49 and 50 does not change with the direction of movement of the armature. If the current flows into the windings 58 in the direction indicated in FIG. 3 by black dots, then the windings can simply be regarded as current-carrying conductors in a magnetic field which is generated by field excitation. In this ¥ else a force is generated at d.en armature windings. In Fig. 3 this force would be directed to the right. As a result of this force on the conductors of the windings, there is a reaction force directed to the left on the source of money, that is the armature 47.Since the armature 47 is freely movable and the conductors are stationary, the armature moves to the left .

When the current through winding sets 65A and 65B is reversed is, as shown in Fig. 4, the force exerted by the windings 58 is directed to the left and this results in a reaction force on the beekeeper 47 to the right.

009833 / OA7A

As can be seen from Fig. 5, "there is a linear relationship between the current I flowing through the windings 58 flows, and the force exerted on the armature 47, so that if the current is held constant, the force exerted on the armature over the entire length of the stroke remains constant.

^{om6mAL WSPECTED}

Claims (9)

Claims \ 1.J Electromagnetic reversing actuator, marked by two sets (65A, 65B) of annularly arranged windings (58) which provide constant current in opposite directions Direction lead »Laraellen (60), which · separate the windings (58) and against each other gaps (62), and one within the windings (58) movable back and forth, constantly magnetically excited Anchors (4-7) with end pieces (49 »5Q), each of which within the axial length of the windings (58) and lamellae (60) and relative to the axial length of the plurality of the windings (58) and the lamellae (60) a small one, but relative to each lamellae (60) and each gap (62) has a large axial length, so that a current flowing through the windings (58) in one direction an essentially constant pushing force in one direction and, if the current is reversed, a constant one Pushing force exerts on the anchor in the opposite direction. 2. Reversing actuator according to claim 1, characterized in that that the distance between the outer ends of the end pieces (49 »50) is smaller than the axial length of the Windings (58) and lamellas (60). 0098 3 3 / (H 7 Λ 3 «Umkehraktuatornachden claims 1 or 2, characterized by an annular permanent magnet (55) said permanent magnet disposed centrally to the windings for generating a constant Srregerfeldes for ö.en armature (47)> substantially 1st and this in two groups (65A ,. 65B) separates » 4- · Reversing actuator according to claim 1, - preferably · in connection with the features of claims 2 and / or. 3j characterized in that the axial length 3 of the end piece (49, 50) ..- is at least equal to the sum of the axial length of a lamella (60) and a lamella gap (62). . '■' .. _; : / 5. Reversing actuator according to claim!, Preferably in Yer mouth with the features of claims 2 and / or 3 j characterized jdaJß the axial ^ length of a i every ükidstückes (49 »50) is at least the same. Sum of the axial length of two lamellas -, (6O) and i columns (62). \: 6. TJiiücehralrfcuator according to claim 1 _} preferably in ter- "connection with one, several-ode ^ .all Herlanalen. Det ¹ claims 2 Ms 5 , characterized., That \ that an annular: Eompensäd: it) 23.9iviicklurig; (, TO). Vörge _} see, -is, which the ErregerwiciI ^ u ^ gen ^ XßS ^^ Ii &'Äwei v ^ ruppen. (65A, 65B) and to improve the linearity of the actuator one with the stroke of the armature (47) carries variable current. / 00 8 833/04 7 4 ■ 7. reversing actuator according to claim 1, preferably in conjunction with one, more or all of the features of claims 2 to 6, characterized in that the Windings (58), the fins (60) and the armature (4-7) enclosed by a non-magnetic housing (4-2-) are and that the lead out of the housing shaft (53) of the armature (47) sii ^ a reciprocating Part is connected. . 3. ümlcehralctuator according to claim 7, characterized in that ".. that 'it serves to operate a heart pump (10) which has a reciprocating, double-acting piston (14), one of which is a cylinder camera (16) at in Catheter to be inserted into the patient's circulatory system (22, 23) is connected, the other cylinder chamber (36) of which is a long (35) of a cylinder (29) is in communication in which one of the actuator shaft (53) driven piston (32) is guided, the two collectors (35 »36) through a liquid coupling (27) are connected so that the movements of the piston (32) of the actuator on the piston (14) of the Heart pump (10). 9. Umfcehralcbuator according to claim 3, characterized gekennzeiclinet, that the second-named chamber (36) of ilerapujiipe and the chamber (35) of the actuator through: a hose line (38) are connected so that the actuator and the Heart pump in places apart from --- ter.it 0098 33 / 047Λ BATH