This invention is related to expandable fastening mean in particular stub axles and shafts. By using expandabl means a very rigid fastening is obtained that is unlikely t losen. Sooner or later however the fastening means must b losened in order to exchange the bearings carried by th shaft. This is however not fully as simple as it sounds: T start with there is always the risk, with the embodiment existing today, that dirt enters into the fastening as well as water, and corrosion and pollution result in that th expandable element will stick so hard that it will becom close to impossible to loosen and remove the shaft. The result is often that violence is used, which in turn can make the renewed mounting impossible, difficult or expens- ive, due to damages on the shaft itself or the fastening brackets.

In view of the above problems an object of the inven¬ tion is to define an improved sealing for shafts fastened with expandable elements and the like. An other object of the invention is to enable and faciliate nondestructive de¬ mounting.

The above objects is in accordance with the invention solved with the characteristics given in the claims. Further advantages and features of the invention are readily appa- rent from the following description of a preferred embodi¬ ment, which in a longitudinal section is shown on the dra¬ wing.

On the drawing one end of a shaft 1 is shown. The shaft is mounted in two brackets of which only one is shown. On the shaft a bearing is arranged. The resulting joint can be used to connect pivotable arms, pistons, piston rods etc.

The shaft 1 has in its outer end a conically tapering part 2 and outside of this a threaded part 3. Between the shaft 1 and the essentially cylindrical hole in the bracket is arranged a sleeve 4 with wedge-like longitudinal

section. The tapering of the conical part 2 of the shaft 1 and the sleeve 4 coincide, and the sleeve 4 is provided with slots extending from alternating ends of it so that the sleeve is easily expandable. In this way the sleeve 4 can be expanded by a forcing the sleeve 4 onto the conical part 2 of the shaft so that the hole 12 is filled up and a secure fixing is obtained for the shaft 1. In order to push the sleeve 4 against the conical part 2 of the shaft a washer 5 is arranged to be pushed over the outer threaded part 3 o the shaft and with an outer diameter less than the hole 12 for the fastening of a joint. The washer is pressed against the sleeve 4 by a nut 11 threaded on the threaded part 3.

The washern 5 has at its outer circumference a threa 10 on which after mounting a sealing and demounting ring is threaded. This is on its towards the bracket turned sid provided with an 0-ring 7. In this way it is certain that n dirt whatsoever can enter into the expanding parts. As a re¬ sult hereof no pollution or corrosion takes place and th parts become easier to demount. Within the concept of th invention it is of course also possible to consider a sea¬ ling ring 6 constituted by a domed nut also protecting th nut and threaded part of the shaft.

In order further to facilitate demounting of the expan¬ dable device the sleeve 4 and the washer 5 are connecte gripping into each other with hooklike circumferencia protrusions. For the sleeve 4 these protrusions are turne inwards and for the washer 5 turned outwards. Preferabl the cooperating surfaces are slightly iclined with the ape of the corresponding cone turned towards the axle 1. In thi way at demounting the nut 9 is first removed and then th sealing ring 6 is unscrewed and again treaded on the washe 5 with the seal turned outwards. The turning of the ring then pulls the washer 5 outwards together with th expandable element 4. The ring 6 is preferably provided wit an outer key grip.

Within the frame of the invention it is also possible to consider the nut and washer 5 integrated with each other, for which case the washern 5 is preferably turnable relative the sleeve 4. In case that the washer 5 does not have any key grip however it is preferably fixed in a turnable direction relative the sleeve so that the fastened sleeve holds the washer 5 against rotation when the ring 6 is turned in order to pull the sleeve outwards.

Instead of the above hooking of sleeve 4 and washer 5 it is of course also possible to consider bajonet grip.

The expandable fastening is in particular intended for the use in heavy machinery to connect piston rods and pistons pivotably with two opposed identical fastenings of the type described. By means of the invention the holes in the mounting brackets can be big enough to allow the shaft 1 to be entered through the holes. Furthermore each end of the shaft is mounted independently and the two fastening brackets will not be subjected to any contracting pressure against each other. Since no pretension prevails the resistance against tension for the total device will be better than otherwise.

Between the two brackets the bearing of the pivotable parts will be arranged and the so to say inner side of the fastenings will be subjected to a constant presence of lubricants under pressure. In order to prevent this lu¬ bricant fr.o seeping away from the fastening means to the outside sealing ring 6 and seal 7 cooperate to keep the lubricant where it should be, including the protection of the sleeve 4 and the surfaces of hole and shaft. When sealing the fastening it is of course not per¬ mitted to subject ring 6 to so great turning toques that the washer 5 is deformed and the sleeve 4 is subjected to removable pressures.

It is of course also possible to arrange a threaded hole in the shaft 2 and use a bolt instead of a threaded

part 3 and nut 11