DE1675159B2 - Woodruff spring acting as a return spring for the armature disk of an electromagnetically operated friction clutch with recesses evenly distributed over the circumference - Google Patents

Description

The present invention relates to woodruff springs acting as a return spring for the armature disks Electromagnetically operated friction clutches with recesses evenly distributed over the circumference.

Such clutches and brakes designed in the same way make diverse demands Armature plates, cushioning, wear-free guidance of moving parts and smooth operation in spite of the most varied of configurations of the elements mentioned, it has not yet been possible to meet them satisfactorily. So were used to generate the required contact pressure initially axially movable armature plates in guide teeth on a central hub body stored without this design was successful because the intermeshing teeth tend to knock out and the inevitable backlash increases with increasing wear is, so that the increasing load surges led to an undesirable shortening of the service life. One therefore went to guide the anchor plates by means of spring-loaded bolts, which exert restoring forces on the anchor plates te so that an air gap occurs when the coil excitation is switched off between the anchor plate and the magnet body. In another design, a part following the armature plate in the mechanical flow of force is connected to the ^{armature plate via an r -both}

ίο Torque transmitting from also towards the coupling part restoring forces exerting spring washer in connection. The magnetic body has except a coil carrier on the excitation coils. When the coil is excited, a force field is formed, its

is lines of force act on the armature disk and this pull towards the magnet body.

Furthermore, the spring washers have already been provided with recesses running in the shape of an arc of a circle, which both radially and peripherally against one another are offset in order to make the disks as flexible as possible. The recesses became U-shaped designed and in the Umiangsrichtung in proportion to each other arranged so that from a closed inner ring radially from the inside to the outside Continuing running spokes in legs directed from the outside to the inside, then the Desired enlargement of the spring travel with a resulting, increased, axial deflection capacity, but in the peripheral direction the spring washer falls be completely stiff, so that forces occurring in the circumferential direction without damping, i.e. abruptly be transmitted.

Since it is the object of the present invention to avoid precisely that, it is characterized on the basis of Magnetic couplings with magnetic bodies, with armature plates that are movable in relation to the latter and preferably with one friction lining for one Hub body having anchor plate, one of the anchor plate following in the mechanical power flow Coupling part with the anchor plate Jber one both Torque-transmitting and axially movable spring washer is in connection, according to the invention in that on the outer circumference of the spring washer individual, in relation to each other by Zwischenräu me separate and axially free in the egg area of their ends Movable spring arms are present, on the one hand in areas of their roots with a spokes on them bearing inner ring, on the other hand with axially upstream and downstream coupling part, namely once in

Areas of their ends, another time of their roots

connected and thus helically below

Storage of an elastically effective restoring force

delivering spring work are deformable.

Although this is no longer new with magnetic clutches,

to the closed inner ring of a circular spring washer, the outer boundary of which is adapted, accordingly spring arms extending in the shape of a circular ring segment in each case at one of their ends in the inner ring let go and the other, free end of the Arms under permanent deformation axially against the To spread the inner ring, so that the thereby helically extending arms only under development can be pushed back by spring counter forces in a space that is bounded by two levels, which the two Belong the inner ring end faces. However, this proposal is based on a problem according to The above deviates completely from that on which the invention is based, because the known spring arms

should serve to solve the different problem the place of a divided and thereby the magnetic flux interrupting, axially extending air gap an undivided, circumferential air gap with the need to set between axially contacting coupling parts realize defined frictional forces and for this purpose the aforementioned To have to provide Federringscheiberr, which accordingly, by means of bolt-shaped sliding pieces against Rotation secured, except for the passive delivery of constant frictional forces to the clutch and Do not actively participate in uncoupling processes. That distinguishes them from the invention, theirs so far unknown, new technical effect consists in the fact that shocks introduced into the clutch are soft and absorbed elastically yielding and, accordingly, only passed on in a damped manner. The spring arms, whose peripheral length corresponds to a part of the circumferential length of the spring washer are in Coupling time still in a plane on the face of the connected magnet body facing the Coupling part. Will the magnet windings energized for the purpose of establishing the coupling state, the anchor plate is tightened and it accordingly takes the spring arms with it, so that their center line now corresponds to one of the coils Helical gear follows, the slope of which increases proportionally to the anchor plate adjustment path. As the spring arm length is constant, brings the transition of the spring arms into the helical thread shape with it that a coupling part connected in the mechanical flow of force while the anchor plate is being tightened undergoes a twist. The ratios can be chosen and determined so that the rotation of the connected coupling part in the case of couplings operated in one direction only in the direction takes place, in which the aforementioned coupling part is to be driven, while with couplings in both Circumferential directions are operated in two directions deformable spring arms are provided. In both cases, the Coupling part, as it would have to occur if the mentioned shape variability in the peripheral direction according to the prior art is absent, rather it causes the forced pre-rotation in the manner described of the coupling part to be driven a bumpless entrainment of the same and a dampened movement transition the driven coupling parts from the rest position. If there is a shutdown so take it the spring arms returning to the starting position due to their resilience, the anchor plate with counter-rotation, but this counter-rotation is irrelevant because it has been detached from the magnet body between the armature plate, so that no force effects occur which have any influence on the run-out initiated by the deactivation of the solenoid coils of the coupling part.

Particularly useful designs of such spring washers are obtained when the spring arms are arranged in a row peripherally one behind the other and each projecting in the same direction over spokes. This arrangement is particularly suitable for clutches which are generally stressed in only one direction, i.e., a torque transmitted in the same direction, in which the spring washer can be arranged in such a way that only tensile stresses generally occur in the spring arms when the torque is transmitted. If, on the other hand, the directions of the torque to be transmitted are constantly changing operationally, it is more advantageous to design the spring washer so that the spring arms are connected to one of the spokes in opposite directions, projecting peripherally over them. If the spring arms are then arranged symmetrically with respect to at least one plane containing the coupling axis, if two planes of symmetry are perpendicular to each other and if they intersect in the coupling axis, then relatively short spring arms with correspondingly high spring stiffness are created, while an arrangement with only one plane of symmetry the spring arms can be longer and extended to the parting plane that is perpendicular to the plane of symmetry short, spring-stiff arms are worked ^r ilL

Of course, there is also the option of using your arms to be arranged symmetrically to more than two levels, which again intersect in the coupling axis and each enclose an angle equal to the quotient of the number 360 and the number of the dividing plane can, such a design leads to relative short, stiff spring arms, which one has in hand, the peripheral length of the spring arms to a set the desired, larger dimension in each case.

Whatever the arrangement of the spring arms, it is useful in any case to use the To design spring washers in such a way that, in addition to spring arms, they have at least one, preferably centrally arranged, has an annular closed part that holds the hub and arm areas of the spring washer together and is the cause of their greater or lesser rigidity.

Since the spring washer is subjected to relatively high loads, especially when the clutch is in continuous operation it has been found to be useful to umzukümpeln the spring washer at the fastening points like a wart or cup and corresponding recesses in the anchor plate and in the mechanical power flow the anchor plate to provide the following coupling part. In conjunction with countersunk screws Connecting means results in the possibility of stresses occurring via linear contacts to be transferred to more or less extensive areas, so that the high stressed spring washers not at the connection and thus clamping points for the formation of There is a tendency for hairline cracks, which significantly increases the service life of such spring washers.

Parts adjoining the recesses, about the anchor plate, made of not ferromifnetiscfwn Substances, charges in the mechanical power flow of the following parts are avoided.

The invention is based on the drawings, which represent a number of embodiments of the invention, explained.

F i g. 1 shows initially in the vertical axis section the basic arrangement of a magnetic coupling designed according to the invention, while

F i g. 2 shows the top view of a spring washer, which is preferably used for magnetic clutches suitable, in which the torque can generally only be transmitted in one direction

F i g. 3 a spring washer design with relative

moderately short and therefore stiff spring arms, which is mainly used for couplings that constantly or in interruptions for the transmission of a torque changing in its directions are to be trained. A spring arm that corresponds to the basic configuration of FIG. 3, but is longer having spring plate is in

F i g. 4 reproduced.

Fig.5 gives the side view of one according to Fig.4 trained spring washer again.

Fig. 6 shows a spring washer formation in plan view, which in its upper part approximately corresponds to the embodiment according to FIG. 3, with elongated spring arms, corresponds, while the lower half of a spring washer according to FIG. 6 is formed approximately as the lower half of a spring washer according to

Fig. 7 in contrast to the spring washer designs according to the F i g. 3 and 4 with just one

nn * t _r «. ™. ~ Λ «-. ^. J, VQ

With respect to which the spring arms are each designed symmetrically, these three radial planes each enclose an angle of 1 20 ° between them.

Fig. 8 shows the left circular section in Fig. I enlarged , while

F i g. 9 shows the top right-hand section of a circle in FIG. 1 illustrated on a larger scale.

Fig. 1 shows the known structure of a magnetic coupling with the coil carrier 1, the excitation coils 2, the hub piece 3 with friction lining 4 and the roller bearing assembly 5, parts 1 and 2 forming the so-called magnetic body of the coupling. There are also the anchor plate 6 and a coupling part 7 connected to the anchor plate 6 and located in the mechanical power flow, via which, for example, the torque is output when the torque to be transmitted is supplied to the part 3, for example. In the arrangement shown, the magnet body 1, 2 can be designed to be stationary, as is indicated at 8.

According to the invention, the parts b, 7 are connected by a spring washer 9 , the design of which corresponds to FIG. 2-7 can be found in detail.

In the embodiment according to FIG. 2, the spring washer 9 has essentially identically constructed spring arms 10, 11, 12, 13 which follow one another in the circumferential direction. The spring arms 10-13 are short, radial arms 14, 15, 16, 17 with a further annularly closed part 18 of the spring washer in connection, which thus holds the spring arms 10-13 via the radial arms 14-17 and the whole the required Gives strength. If the points are called the roots of the spring arms at which they are directly connected to the common retaining ring 18 via the radial arms 14, 15, 16, 17, the roots can be used together to connect the spring washer either to the armature disk 6 or serve to connect to the coupling part 7. The same applies to fastening points formed by the arms with the difference that if the fastening points located at the roots are used to connect to the armature disk, the fastening points formed by the spring arms are used to connect to the coupling part 7, the reverse of course also applying accordingly In the example case it is assumed that the roots serve to connect the spring washer 9 to the anchor plate 6. In this case, the bores 19, 20, 21, 22 are penetrated by screws, the threaded shafts of which are received in the anchor plate 6 . On the other hand, there are screws in the bores 23, 24, 25, 26, the threaded shafts of which are received in the coupling part 7. The arms 10, 11, 12, 13 are, as in FIG. I shows, when the spring washer 9 is installed, it is bent out of its center plane. Since the bent arms seek to spring back into the starting position, restoring forces occur which, in FIG. 1, tend to draw the anchor plate to the coupling part 7. If no more excitation current occurs in the magnet coils 2, the armature plate is withdrawn into the starting position in which it was before the tightening under the action of the excited coils 2, that is, into the abutment position on the spring washer 9 with the spring arms retracted in its plane . The uncoupling position is thus achieved. The armature plate 6 changes into the coupling position at the point in which the coils 2 are excited, the armature plate 6 is applied while overcoming the spring counteraction , and is carried along by the friction lining 4. The spring arms 10-13 bent up out of the center plane of the spring washer 9 now act as a torque transmitter. So that there is here no undue compressive stresses the spring arms, it is expedient that the attachment points 19-22 the fastening points 23 to 26 are advanced in the direction of the torque to make it in the arms 10-13 vorwieg ^first . \ d occurs when tensile loads occur. This means that seen in the plan view of FIG. 2, the torque to be continuously transmitted should occur predominantly in the counterclockwise direction.

It brings the operation of the coupling with that alternating torques occur, as are embodiments of spring washers of FIGS. 3 and 4 shall be used advantageously as spring washers to Fig. 2. In the case of the spring washer of Fig. 3 enter the relatively short spring arms 27-30 with the radial arms 31, 32 as connections to the support ring 18 in that the spring washer is formed symmetrically to a plane which intersects the plane of the drawing in the straight line 33-33. The connection points 34, 35 with one of the parts 6, 7 can now be spatially put together, while the four further fastening points 36-39 are required to serve the connection with the other coupling part.

While the arm ends here have relatively large distances from the parting plane 40-40 , these distances are in the exemplary embodiment according to FIGS. 4 and 5 much smaller, that is, the lengths of the spring arms 27-30 longer. For this reason, it is advisable to make the connection points 41, 42 and 43, 44 separate from each other again in order to avoid the occurrence of overstressing on the spring arm roots. Otherwise, a spring washer design differs according to FIGS. 4 and 5 not significantly different from that of FIG. In particular, the feature that the spring washer is warty at the fastening points is in agreement.

_M or cup-shaped are turned upside down, like the one from FIG. 5 at 41, 42; 36, 37; 38, 39; 43, 44 can be seen in FIG. 8 shows that it is thus possible, in conjunction with the use of fastening screws 45 with countersunk heads 46, at each fastening point of the spring washer be to create extensive contact surfaces with neighboring parts, so that area-wide contact takes place at the point an otherwise only achievable linear contact, which makes it possible to compare the loads

moderate and especially to avoid the formation of hairline cracks that would occur if only one linear contact between the spring washer and adjacent Klipoppelstteile be realized could.

The upper half of the spring washer design according to FIG. 6 can be derived from the upper half of a spring washer design according to FIG. 3 and ¹ think in their lower half composed of the lower half of a spring washer, which is shown in FIG. 7 is shown and will be explained later / ti. The spring disc design not I- i g. h allows it. to satisfy certain healing cases in a particularly expedient manner.

Hei the l'ederscheibenaiisfühning after I · 'i g. 7 it is the radial planes 0-47, 0-48 and 0-49. / ti which spring arms are each designed symmetrically. These three radial planes intersect in the coupling! ■. ·. ·. You j-.chüe'Jeri / wipes;!; give yourself a hint! ·. ".> ■ <120 a. \ '. The tax offices 50, 51, 52 come on

Coupling part 6 or 7 or 5J-58 on coupling part 7 or 6 on.

8 it was already mentioned that as a result the wart-like Umkümpelung or crankings that the spring washer 9 at the attachment points has, in connection with corresponding recesses in the receiving part and further in connection with Screws 45 with countersunk head 46 thereby increased strength at the connection points what is achieved is that extensive, surface contacts occur here.

In some cases it can be / wake-up that nodular or cup-shaped depressions 59 are not directly on the hikingsurfaces of the recesses in the acceptance part, rather than as Pick-up part special liinsat / slücke 60 from nichiferromagnetic Materials, for example brass, to be provided, as shown in FIG. I and 4 for example

Here / u 3 sheets of drawings

Claims (1)

1 Patent claims: 1. Woodruff spring acting as a return spring for the armature disk of an electromagnetically operated friction clutch with on the circumference evenly distributed recesses, thereby characterized in that on the outer periphery of the disc spring (9) extending in the circumferential direction and individual spring arms arranged at a radial distance from a closed inner ring (18) (10-13; 27-30) are provided on spokes (14-17; 31-32), over these after at least one Projecting peripherally towards the periphery, attached radially and connected to them, the spring arms in Areas of their transitions into the spokes and opposite ends to these Receiving connecting means (45, 46) with adjoining coupling parts (6, 7) serving Own training. 2. Friction clutch according to claim 1, characterized in that the spring arms (10-13) in Row peripherally behind one another and each in the same direction, over the spokes (! 4—17) cantilevered, are arranged (Fig. 2). 3. Friction clutch according to claim 1, characterized in that the spring arms (27-30) according to mutually opposite directions on one of the spokes, projecting peripherally, connected (Fig. 3-7). 4. Friction clutch according to claim 3, characterized in that the spring arms (27-30) in Are arranged axially and metrically with respect to at least one radial plane containing the coupling axis (Figs. 3-7). 5. Friction clutch according to einni of claims 1-4, characterized in that the woodruff key (9) at the connection points with adjacent Coupling parts (6, 7) bulb-like or cup-like umkümpelungen (59) or spring arms (10-13; 27-30) and that the adjacent coupling parts close the Umkümpelungen have receiving recesses (Fig. 8,9). 8. Friction clutch according to claim, characterized in that the recesses are provided in insert pieces (60) made of non-ferromagnetic materials.