DE1932790A1 - Torque limiting clutch - Google Patents

Description

8076-69 / Dr.v.B / E

Institute for Plasma Physics G.m.b.H. 8046 Garching

Pre- torque limiting clutch

The present invention relates to a torque-limiting clutch with two for the transmission of a torque in a non-positive manner interconnected components that when exceeded a predetermined torque can be rotated against each other are.

The known torque-limiting clutches are generally so-called slip clutches that work on the principle of friction. The torque is adjusted via two transfer barem pressure against each other pressed surfaces, which at If a limit torque is exceeded, slide frictionally on each other. . ;

The disadvantage of the known slip clutches that they wear out quickly and do not work reproducibly because of the changes that necessarily occur in the surfaces that slide on each other. This is especially true for high speeds and high torques. Slipping clutches are also very sensitive to soiling. .

Another disadvantage of slipping clutches that are based on the Working on the principle of friction, brings the difference between and sliding friction with it; To tear off the rubbing surfaces from one another, i.e. to initiate spinning, a higher one is required Torque required than it is then when sliding on each other

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Surfaces is transferred. Another weakness of the friction clutch is the non-linear dependence of the frictional force of the relative speed of the surfaces sliding on each other a The transmitted torque is therefore not independent of the Speed, it rather increases with increasing speed, so far significant changes in the coefficient of friction do not occur as a result of the heating of the surfaces rubbing against one another.

There are also electromagnetic clutches known at which a torque is generated by induction of eddy currents. In contrast, these electromagnetic clutches have friction clutches the advantage that they are wear-free. Electromagnet is before clutches are suitable, however; not for applications where the speed of the aagetriefeexien shaft is strong Is subject to fluctuations, since the transmitted torque only is generated by a certain, load-dependent slip.

The present invention is accordingly gave up of overcoming the disadvantages of the known torque-limit-r m avoid the couplings and to provide such coupling a © that works reproducibly, long life has ₃ even if they are operated at high speeds and / or for the transmission of high torques is used ₉ and in which the torque transmitted when spinning is practically equal to the _{limit torque 9} at which spinning occurs ₃ and is essentially independent of the speed.

This object is achieved according to the invention in a torque-limiting Coupling of the type mentioned above is achieved in that the two components each have a track, in at least one of the components, preferably in both, consists of an elastic material exhibiting considerable mechanical hysteresis, and that between the two raceways - rolling bodies are arranged in the manner of - 'one.' when transmitting a torque that is less than the specified torque (limit torque), the two components by deformation of the existing from the elastic material

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Coupling the raceway or raceways with one another in a non-positive manner, but walking on the if the limit torque is exceeded unroll the elastic material.

In the torque-limiting clutch according to the invention, a surface effect, namely friction, is not used as in the known slip clutches, but a volume effect, namely the flexing work in a material with elastic hysteresis to transmit and limit a torque. The transmitted torque is therefore also through Ver ^; dirt practically not affected. In contrast to a friction clutch, there is no excessive torque when starting. The wear of the milled material is orders of magnitude less than that of surfaces sliding on one another.

The two raceways and the rolling elements can according to Art a ball or roller bearing, e.g. an axial ball bearing or a tapered roller bearing. .

The elastic material with elastic hysteresis is preferably an elastomeric material, for example natural rubber, synthetic rubber or a rubber-elastic plastic, for example a plastic made of ethylene glycol-adipic acid polyester in combination with naphthalene-IS-diisocyanate, as it is commercially available under the trade name ¹¹ Vulkollan " .

According to one embodiment of the invention, the two raceways are pressed against one another by a preferably adjustable spring.

According to a further development of the invention, there is a pressure device provided, which reduces the contact pressure of the rolling elements on the runway or runways made of the elastic material or cancels when the transmitted torque disappears, and the rolling elements when transmitting a significant torque up to a certain maximum amount in the elastic Material presses. By such a pressure device

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become permanent or longer lasting. Avoid deformations of the elastic material that can occur under certain circumstances ₃ when the rolling elements are pressed into the roller track or roller tracks made of the elastic material at the same point for a longer period of time.

The pressure device can, for example, be a non-self-locking one Contain cam or cam arrangement that the raceways at j Transmission of a torque by a certain, limited ■■! Line approaches each other. j

fc Because the limit torque and the transmitted torque practically not from the surface properties of the rolling elements and runways, the runways and the rolling elements can depend be arranged in a sealed housing that has at least one Contains liquid material at operating temperature which corresponds to the im elastic material dissipates heat to the housing. That Material used for heat dissipation can e.g. be a liquid, such as water, or a lubricant such as oil. As the heat in; primarily near the surface of the runway from the consists of elastic material and the heat-dissipating material is kept in strong motion by the rolling elements, is a very effective dissipation of the heat occurring when turning the clutch according to the invention is possible.

The torque limiting clutch according to the invention can be used instead of the known slip clutches, e.g. for winding machines, magnetic tape devices and possibly also for synchronous transmissions of motor vehicles and the like.

The invention is explained in more detail below with reference to exemplary embodiments; show it:

Pig * 1 an axial section through a torque limiting Coupling according to the invention, which is constructed in the manner of an axial ball bearing,

Fig. 2 is a section along A-A in Fig. 1; "009882/1 UO--

Fig. 3 is an end view of a torque limiting Coupling according to a second embodiment of the invention with removed cap, and

4 shows an axial section through the coupling according to FIG. which is constructed in the manner of a tapered roller bearing.

Corresponding parts are included in both embodiments the same reference numerals have been given. ,

. In Figures 1 and 2 as an embodiment of the invention illustrated torque-limiting coupling comprises a reasonable \ exaggerated Wele 1, on which a bearing shell 2 of a commercial; Double axial deep groove ball bearing is attached. Balls 3 run on the raceway of the bearing shell 2 and are located in a non-coffin; placed cage. The other bearing shell 5 for the balls

3 is provided with a rubber pad 4 »between the rubber pad 4 facing away from the bearing shell 5 and a third Bearing shell 7 is a second ball ring .6 arranged. Between j the third bearing shell 7 and two on the right end of the shaft I.

1 screwed lock nuts 9, 10, a spring 8, shown in plan view in FIG. 2, is arranged ₉ through which the bearing shells

2 and 5 against each other and thus the balls 3 in the rubber pad

Are pushed 4 * The right end of the shaft 1 is j stored in a radial ball bearing 11, a clutch housing having a stub shaft 12 ,. where the transmitted torque can be removed is taken up ₉ of ". The left-hand in Fig. 1 the end of the The housing is attached to the bearing shell 5.

During operation of the clutch according to FIGS. 1 and 2, torques transferred between components 1 and 2 without slippage as long as these torques a specified amount (limit torque do not overwrite. When the torque is the specified amount however, the balls start 3 on the rubber pad 4 to unroll and do flexing work. The contact pressure between the balls 3 and the rubber pad 4 and thus the limit torque leading to the spinning can be controlled by means of the lock nuts 9, 10 can be set within wide limits.

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There is practically no sliding friction but only one rolling friction When the balls and their raceways occur, the wear is significantly lower than with slip clutches, which work on the principle of friction. The wear can be further reduced by lubricating the balls and the running surfaces. This can be done by means of a fat take place or you can also use the present slip clutch in a liquid, e.g. an oil bath, because the surface properties the raceways and the balls practical P do not enter into the limiting torque or the torque transmitted when spinning.

The coupling according to the invention can also be arranged in a sealed housing which contains a lubricant and coolant, as is the case with the exemplary embodiment shown in FIGS. 3 and 4. . . .

. Die.in Figures 3 and k 'shown coupling ^1, according to the Er ^"-: the invention contains for torque transfer and limitation rolling bodies 3' in the form of tapered rollers ₉ between the components 2 * and 12". arranged aid, both of which are provided with a layer k ^% or k ⁿ made of a material with considerable elastic hysteresis. The arrangement corresponds to a Kegelroilen- "storage. The device 12" _s forms a housing which is sealed against the shaft by a simmer ring 13. At the other end the housing is a cap 12 durch'- * -: ,, complete- carrying the stub shaft 12 with i; "Your component 12" is screwed and is sealed against it with an O-ring l4. The housing can be provided with cooling fins and contains a material ₉ that lasts the rolling elements 3 'and the running surfaces for these rolling elements forming the supports 4' and 4 "cools." Corn can, for example, use a liquid such as oil or water. ■

The torque limiting clutch ^ according to the invention can also be constructed in the manner of a Hadial ball or roller bearing. There is then ζ.B. the inner tread for Balls or rollers from the outer surface * of a rubber ring

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or the like. _s which is mounted on a shaft. With such an arrangement, the limit torque can be set by axially compressing the rubber ring »

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Claims (11)

Claims l.yTorque-limiting coupling with two components that are force-tightly coupled to one another in order to transmit a torque and that can be rotated against each other when a specified limit torque is exceeded,. characterized in that the two components (1, 12) each have a raceway which, in at least one of the two components, consists of an elastic material (4, 4 ', 4 ") exhibiting considerable mechanical hysteresis, and that between the two raceways Rolling bodies (3> V) are arranged that force-fit the two components when a torque is transmitted that is less than the limit torque through deformation of the raceway or raceways made of the elastic material, but when the limit torque is exceeded, they walk on the elastic material roll off 2. Coupling according to claim 1, g e k en η ze i c h η e t by a device (8, 9, 10) for adjusting the Force with which the two raceways are pressed against each other. 3 · Coupling according to claim 1 or 2, characterized "ge k en η draws η e t that the two career paths and the rolling elements are shaped like a roller bearing. 4. Coupling according to claim 3, d a du r c h g e - k en η ζ ei ch η et that the two raceways (2, H) and the rolling elements (3) are designed in the manner of an axial ball bearing (Pig. 1 and 2). 5. Coupling according to claim 3, characterized g e - k en η ζ e ic h η et that the two raceways (V, H ⁿ ) and the rolling elements (3 ») are designed in the manner of a tapered roller bearing (Fig." 3.iuid.il ·) .. 0098 8 2/1 UO 6. Coupling according to one of the preceding claims, d adurch characterized in that the elastic j Material is an elastomeric material, in particular a natural or synthetic rubber or a rubber-elastic plastic. 7. Coupling according to one of the preceding claims _s d adurch geke η η ζ eich η et that the two raceways are pressed against each other by a preferably adjustable spring (8). ~ 8. Coupling according to one of the preceding claims, marked g by a pressure device, which the contact pressure of the rolling body on the runway or Rolling tracks made of the elastic material lowers or cancels when the transmitted torque disappears, and the Rolling body when transmitting a significant torque up to> a certain maximum amount in the elastic material presses. 9. Coupling according to claim 8, since d u r c h g e - k e η η shows that the pressure device is a non-self-locking Contains cam or cam arrangement that the taps when a torque is transmitted between the two Components approach each other by a certain, limited distance. 10. Coupling according to one of the preceding claims, d adurch marked that the career paths and the rolling elements in a lubricating and cooling liquid to run. 11. Coupling according to one of the preceding claims, characterized in that the two raceways and the rolling bodies (3 ¹ ) are arranged in a sealed housing (12 ', 12 "), which is an at least when operating 0098 8 2/1140 temperature liquid, heat from the raceways to the housing transmitting and preferably also the raceways and the rolling elements Contains lubricant material. 0098 & 2 / IUO Lee rse i te