DK142207B - Locking mechanism for rotating turbine shafts. - Google Patents

Description

142207

The invention relates to a blocking mechanism for rotary turbine shafts, in particular turbocharger shafts, which can be mounted on the compressor side and / or turbine side of the turbocharger and have elastic intermediate links.

In the event of a turbocharger failure in a diesel engine plant, e.g. in the event of damage to blades or bearings, it is necessary to bring the turbine shaft to a standstill and, without charge, to continue the operation of the previously loaded diesel engine to avoid total shutdown of the system. When the turbocharger is stopped, the exhaust gases of the diesel engine continue to flow through the now stationary turbine vanes in the axial direction, thus exerting a torque on the turbine wheel. In order to prevent rotation of the turbocharger shaft, it must be blocked by a braking mechanism which exerts a corresponding torque acting in the opposite direction. The previously known and used blocking mechanisms may e.g. be located on the compressor side and on the turbine side. For this purpose, two identical blocking mechanisms are generally used. However, to compensate for manufacturing tolerances and axial thermal extensions of the blocked shaft, an elastic intermediate is provided on the turbine side between the blocking mechanism and the turbine housing.

However, with the known method of blocking the shaft of the turbocharger, it is a disadvantage that the torques acting in the opposite direction exerted by the two blocking mechanisms are very different from one another. The turbine wheel is arranged symmetrically with respect to the end bearings of the turbine shaft, whereby the weight arm becomes substantially longer on the compressor side. Thereby the torque acting on the compressor side is less than the opposite torque acting on the turbine side. This can result in distortion or overloading of the shaft end.

The object of the present invention is to provide a blocking mechanism which can be easily attached to any available location on the turbine shaft. Preferably, the required opposite torque must be provided utilizing the relatively short distance of the locking seat from the turbine wheel so as to obtain a torsion-free connection.

This object is solved according to the invention in that an annular flange, which can be fixed on a turbocharger housing and a corresponding annular, internally flange mounted on the turbine shaft by means of a spring retained by a stop ring is so connected that they are axially displaceable relative to the and that clamping elements consisting of a slotted inner sleeve, an outer sleeve and tensioning screws, of which the inner sleeve sits on a shaft on the shaft and with a radially outwardly tapered surface abutting the outer sleeve, are arranged in a recess in the inner flange in such manner, that the turbocharger shaft can be fixed by tightening the tightening screws.

In particular, the advantage of this mechanism consists in that the connection of the outer flange to the inner flange by means of with pins provides an axial displacement of the two flanges with respect to each other, thereby allowing in a simple manner an equalization of mechanical and thermal extensions. The placement of clamping elements in the inner flange as well as a slotted inner sleeve 10, which sits on a step on the turbocharger shaft, causes the shaft to be blocked by friction. By means of placing the spring between the outer flange and the inner flange, it is achieved that the outer flange, after being dismantled, is again pushed back to its original position.

Conveniently, the carrier pins may be disposed in axially directed bores disposed in a lateral manner that their longitudinal axis lies in the separation plane between the outer flange and the inner flange, and the clamping members may consist of an outer sleeve and clamping screws, and the outer sleeve and slotted inner sleeve may have tapered surfaces.

By means of clamping elements consisting of an outer sleeve, clamping screws and a slotted inner sleeve, it is possible to simply pull the tapered inner sleeve and outer sleeve conical surfaces towards each other in a simple manner in such a way that the slotted inner sleeve correspondingly strongly pressed against the turbocharger shaft, preferably against a step on it, thereby obtaining a friction connection.

In addition, threaded bores and thrust surfaces may be arranged alternately over the circumference of the outer sleeve.

By means of this alternating arrangement of threaded bores and thrust surfaces over the circumference of the outer bushing, it is possible to easily use the tensioning screws both for blocking the turbocharger shaft and for releasing the blocking mechanism, as these can be inserted into corresponding bores in the inner flange.

According to a further preferred embodiment, the extractor thread is arranged over the circumferential flange of the outer sleeve and the threaded holes for inserting the clamping screws are arranged through the inner flange and threaded holes in the outer sleeve.

Thereby, the advantage is obtained that the locking mechanism can be fixed to the turbocharger shaft without the use of special clamping or pushing screws and again released from it by the same clamping screws.

In the drawing, an embodiment of the blocking mechanism according to the invention is illustrated in simplified form. The drawing in the drawing shows: fig. 1 shows a blocking mechanism according to the invention in a blocked position; and FIG. 2 shows the same blocking mechanism as shown in FIG. 1 in the detached position.

In FIG. 1, there is seen a housing, preferably a turbocharger housing, in which a turbocharger shaft 2 is mounted. The turbocharger shaft 2 has a step 3.

On the housing 1 is secured by means of fastening screws 6 an annular outer flange 4 associated with a blocking mechanism, which at the end at which it is attached to the housing 1 has a stop ring 5, with which a spring 14 protruding radially inwards past the inside of the outer flange is held against the end surface of the outer flange. An axially displaceable axially displaceable inner flange 7 with respect to the outer flange 4 is secured to 15 by means of 15 clamping elements consisting of a slotted inner sleeve 8, an outer sleeve 9 and clamping screws 10 under frictional engagement with the turbocharger shaft 2.

To receive the clamping screws 10, the inner flange 7 is provided with a bore 11. Both the slotted inner sleeve 8 and the outer sleeve 9 have 20 tapered faces 12. In the separating plane of the inner flange 7 and the outer flange 4, spring pins 13. The spring 14 rests with spring force. the end face of the inner flange 7. The inner flange 7 is formed on its inner face facing the turbocharger shaft 2 as a guide 15 resting against the turbocharger shaft 2.

In FIG. 2, the locking mechanism is shown in the loosened position, and parts similar to those in FIG. 1 are designated by the same reference numerals. The fastening screws 6 are detached from the housing 1, and at the same time, the clamping screws are screwed into an expander thread 16 in the inner flange 7 and press with their end face against an exporter surface 17 on the outer sleeve 9, thereby releasing the tapered inner sleeve 8's and the outer sleeve 9's tapered surfaces 12 one another, so that the locking mechanism can be removed from the shaft collar 3. In order to prevent the slotted inner sleeve 8 and outer sleeve 9 from falling out of the inner flange 7 from the mechanism, a locking ring, preferably a retaining ring 18, is arranged in the inner flange 7.

The operation of the locking mechanism is as follows: For blocking of the turbocharger shaft 2, the part of the locking pin 13 provided by the outer flange 4, the inner flange 7, the stop ring 5, the compensating spring 14 and the separating plane 13 of the inner flange 7 and the outer flange 4 is provided with the locking mechanism. on the turbocharger shaft 2. The outer flange 4 is fastened by means of the fastening screws 6 in the housing 1 and the inner flange 7 is clamped on the turbocharger shaft 2 by means of the clamping elements 8, 9 and 10, with the tensioning screws 10 projecting through the bores 11 in the inner flange 7. in the threaded bores 19. By screwing the tightening screws 10 into the threaded bores 19 of the outer bushing 9, the clamping elements 8, 9 are displaced axially in such a way that by means of the tapered surfaces 12 they push the slotted inner bushing 8 into frictional engagement with the turbocharger shaft 2, preferably with axle. -10 the step 3 in such a way that the shaft is blocked. The design of the blocking mechanism in the inner flange 7 and the outer flange 4 allows for a displacement of the blocking mechanism relative to the turbocharger shaft 2. The spring 14 returns the inner flange 7 in its normal position with respect to the outer flange 4. The driver pins 13 transmit the torque 15. from the inner flange 7 to the outer flange 4. To remove the locking mechanism, the clamping screws 10 are unscrewed from the threaded bores 19 of the outer sleeve 9 and screwed in so far between the individual bores 11 in the inner flange 7 that the threads 16 of the outer sleeve abut against the outer surface of the outer sleeve 9. 17. At a further 20 voltages, the outer sleeve 9 is pushed away from its slotted inner sleeve 8fs conical surface. The range of movement of the clamping screws 10 is limited by their thread length. After unscrewing the fastening screws 6 of their bores in the housing 1, the locking mechanism can be pulled off the turbocharger shaft 2. By means of the guide 15, the inside diameter of which 25 corresponds to the outside diameter of the turbocharger shaft 2, mounting and disassembly of the blocking mechanism is also facilitated and clamping is also avoided.