1. A supporting structure of a multiple-plate clutch, comprising:
a clutch drum having an outer cylindrical portion in which a spline is formed on an inner periphery, an inner cylindrical portion, and a bottom wall portion formed at one axial end;
a hub in which a spline is formed on an outer periphery;
a piston for pressing, in the axial direction, a first frictional engaging element which is spline-fitted to the inner periphery of said outer cylindrical portion and a second frictional engaging element which is spline-fitted to said hub,
wherein said multiple-plate clutch is bearing-supported at both sides, in the axial direction, of a position of a center of gravity of said multiple-plate clutch,
wherein said bearing-supporting is provided at a portion of a front edge side of said of said inner cylindrical portion and at a portion of the bottom wall side of said inner cylindrical portion, and
wherein said bearing-supporting at said portion of said bottom wall side is provided integratedly with a thrust bearing for said bottom wall portion.
The claims below are in addition to those above.
All refrences to claims which appear below refer to the numbering after this setence.
1. A shut-off device comprising a single-part housing insertable in a pipeline, and a butterfly valve swivellable by a drive shaft wherein said butterfly valve in its closed position is sealed off from the housing and from the pipe connection, by a distensible entropy-elastic annular seal of U-shaped cross section to which fluid can be applied, with said annular seal being held by a backup ring on a face of the housing, characterised in that by means of two annular projections (11, 12) which face each other, the annular seal (7) engages one annular groove (13, 14) each in each face (15, 16) of the backup ring (6) so as to provide a seal; in that each of the lateral external areas (17, 18) of said annular seal (7) comprises an integrated projecting sealing ring (19, 20), and in that the backup ring (6), in its area situated outside the annular seal (7), is attached to the housing (2) by means of several conventional hexagon socket screws (8).
2. The shut-off device according to claim 1, charactertised in that the cross-sectional shape of the facing annular projections (11, 12) of the annular seal (7) matches the cross-sectional shape of the accommodating annular groove (13, 14) so as to provide a positive fit, and with the projecting sealing rings (19, 20) being arranged in the region of these projections (11, 12), on the two lateral external areas (17, 18) of the annular seal (7).
3. The shut-off device according to claim 1, characterised in that the sealing rings (19, 20) integrated in each of the lateral external areas (17, 18) comprise a cross section which is in the shape of a semicircle or a segment of a circle.
4. The shut-off device according to one of claims 1, characterised in that the backup ring (6) comprises a fluid pressure chamber (22) at its internal circumferential area (23); said fluid pressure chamber (22) being in the shape of an encompassing annular groove, with a fluid connection pipe (24), which is sealed so as to be fluid-proof towards the external atmosphere, directly leading into said annular groove so as to exert pressure on the annular seal (7).
5. The shut-off device according to one of claims 1, characterised in that the backup ring (6) is placed onto the matching face (33) of the housing (2) and encompassed by centring turned grooves (36, 37) only in the two diametrically opposed regions (34, 35) of the lead-through of the shaft (3) of the butterfly valve (4).
6. The shut-off device according to one of claims 1, characterised in that the butterfly valve (4) is swivellable into and out of its closed position without touching the annular seal (7), and in that said annular seal (7) is distended only after the butterfly valve (4) has reached its closed position and is depressurised before the butterfly valve (4) is swivelled out of its closed position.
7. A shut-off device according to claim 6, characterised in that in the non-pressurised state of the entropy-elastic annular seal (7), there is an all-round annular clearance (S) between the area of the external circumference (28) of said annular seal (7) and the area of the external circumference (29) of the butterfly valve (4).
8. A shut-off device according to one of claims 1, characterised in that at its face (30) pointing away from the annular seal (7), the housing (2) comprises an O-ring (32) inserted in an annular groove (31), thus sealing off said housing (2) and the pipeline end abutting against this face (30) in a way which is known per se.