Abstract:
Flexible coupling which can rotate in both directions, comprising two coupling parts connected to each other by torque transmitting simultaneously loaded resilient rolling elements which are mounted in pockets, each of which is defined by two adjacent cavities in said two coupling parts.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a flexible coupling which can rotate in both directions and mainly comprising two coupling halves one part of a half projecting into the other, said halves being connected to each other by torque transmitting simultaneously loaded resilient elements which are mounted in cavities provided in said coupling sleeves. A similar but different coupling is disclosed for example in the British patent specification 111.807. 
     An object of the invention is to improve a coupling of the said type by introducing a simple and effective means for realizing a precompression in said resilient elements which increases the working capacity and applicability of said coupling. The improvement also provides a flexible coupling having resilient elements of different densities and characteristics through which the capability of said coupling will be enlarged. Another advantage is obtained by the fact that replacement of the coupling parts can be achieved by handling simple tools and without displacing the units which are connected to each other by the improved coupling. 
     SUMMARY OF THE INVENTION 
     According to the invention the cavities within the halves of the coupling, in accordance with the longitudinal sectional view, have a spherical or an oval form and fully encapsulate the torque transmitting elements, whereby one half of the coupling forming a part of said cavities, comprises at least two different proportioned parts by means of which a precompression in said elements can be achieved. 
     Advantages of the coupling according to the invention are characterized in that, at least one of the coupling halves, which can have the form of a ring or dividable block parts, covers a larger surface of a resilient element; good accessibility to the resilient elements is obtained; by using bolt connections, for example, between said coupling parts, an effective adjustment of the precompression in the resilient elements is possible, whereby said resilient elements will conform to the shape of the cavities. In use the coupling will not create axial force but instead can absorb reasonable axial load in both axial directions, and within certain limits is axially self-adjusting. The new coupling permits a greater misalignment of the shafts of the units being coupled, as compared with other known coupling designs, without unduly impairing the working conditions. The coupling is self-centering, and it allows a reasonable parallel mis-alignment. 
    
    
     The invention will be explained further by reference to the drawing, whereby advantages and other featured of the invention will become evident. 
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a longitudinal sectional view of a coupling according to the invention. 
     FIG. 2 is a cross-sectional view of the coupling taken along according to line II--II of FIG. 1. 
     FIG. 3 is a fragmentary sectional view of the coupling of FIG. 1 provided with specific torque transmitting elements. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     According to FIG. 1, coupling 1 comprises coupling halves 2 and 3, of which coupling half 3 comprises of parts 4, 5 and a flange part 6. Coupling part 4 which is larger than part 5 contacts the resilient round, spherical or the like element 7 over a larger area than coupling part 5, with the resulting advantage that by removing only part 4, the interior of the coupling is easily accessible, i.e. the elements 7 can be exchanged in a simple and quick manner without disturbing the position of the other parts or the coupled units. Depending on the application of the coupling concerned, coupling parts 2, 4, 5 and 6 can be made of different materials. 
     Coupling 2 is furthermore connected to a shaft 8 (indicated by centre-line) by means of e.g. a key connection 9. The separable coupling parts 4 and 5 are secured to part 6 by bolt-connections 10; flange part 6 is connected to a shaft 11 also by a key connection 12. By means of the bolt connections 10 a precompression. in the resilient elements 7 is imposed. In relation to this, the halves 2 and 3 are provided with spherical or oval-like cavities 13 and 14 respectively which have the same dimensions. The distance D of the cooperating cavities 13 and 14 however is smaller than the diameter of the ball-like element 7, while the distance in axial direction of said cavities is larger than the said ball diameter. Due to this arrangement, after tightening the bolt connection 10 during mounting, the resilient elements will adopt the form of said cooperating cavities 13 and 14, whereby the above mentioned advantages will be obtained. Further, the compression of the resilient ball-elements 7 give the coupling suitable damping properties against torsional vibrations. 
     According to the view in FIG. 2, however, the resilient elements 7 are fully enclosed in radial direction by the cavities 13 and 14 of the coupling halves 2 and 3, so that an effective transmission of torque or power in both directions is still guaranteed. In these preferred embodiments coupling half 4 comprises segments 4A, 4B and 4C which fit into each other and are connected to each other by means of bolt-connections 15 arranged within the periphery of the coupling 1. This arrangement makes it possible to remove the coupling sleeve 4 from the coupling in a simple and easy way, preventing for example axial displacement of the unit or machine to which the coupling is connected. It is possible to compose both sleeveparts 4 and 5 of such separable segments, connected to each other by bolts 15. The application of a relatively large number of adjusting bolts 10 furthermore permits an easy precompression of the resilient elements 7. 
     FIG. 3 shows a part of the longitudinal sectional view of a coupling according to the invention, in which coupling half 2 is axially displaced in relation to coupling half 3. With this invention such a displacement of shafts 8 and 11 now can be tolerated within certain limits, without resulting in unduly axial loads in the connected or coupled units or machine-parts. This is chiefly due to specific cavities being present between the coupling halves 2 and 3 and elements 7, which elements become slightly oval owing to the precompression, wherein space 16 in the cavities 13 and 14 permits such a relative flexible coupling system. In this preferred embodiment, elements with a resilient outer layer 17 are provided with a reinforced (i.e. less resilient) core 18, which prevents the situation where the elements 17 would suddenly cease to function e.g. during overrunning, such as due to the fracture of the resilient material for example by overheating. 
     It is pointed out that assembly, disassembly and subsequent adjustment of the coupling can be carried out by one person handling simple adjusting tools. 
     The invention is otherwise not limited to the embodiment described in the foregoing, but also relates to those embodiments of a coupling, in which the transmission of torque or power in both directions is effected by means of resilient elements arranged in said coupling.