FR2529988A1 - LABYRINTH TYPE SEALING, IN PARTICULAR FOR ROTATING MACHINES SUCH AS PUMPS OR THE LIKE - Google Patents

Abstract

A. LABYRINTH TYPE SEALING, ESPECIALLY FOR ROTATING MACHINES SUCH AS PUMPS OR SIMILAR. B. CHARACTERIZED IN THAT TWO RINGS ENGAGED IN ONE THE OTHER WITH CLEARANCE, ARE ALTERNATED, THE EXTERIOR RING 4 BEING PRESSED IN BALEAGE 15 AND THE INTERNAL RING 2 BEING SECURED TO THE PRESS ON THE SHAFT 10 WITH A RING 3 PRESSED ON SHAFT 10 OR IN BORE 15 AND ENGAGED WITH CLEARANCE IN BORE 15 OR ON SHAFT 10. C. THE INVENTION APPLIES TO SEALING GASKETS ROTATING MACHINE SHAFTS.

Description

1.- "Labyrinth type seal, in particular

  for rotating machines such as pumps or similar

  The present invention relates to a labyrinth type seal gasket for

  to hydraulic rotary machines.

  Labyrinth seals have been known in the art for a long time and are

  implemented in the case where support bearings of

  are exposed to the pressure of gaseous fluids or

  high-viscosity materials In particular, there are known

  labyrinth sealing elements, in which the rotating part and the stationary part have rotational profiles adapted to each other by shape engagement. In order that neither the rotor nor the stator themselves can

  are not subject to friction wear, insert

  in the labyrinth seal pro-

  plastic discs which are subject to wear The conformation, by form engagement, of the rotor

  and the stator requires a separation of the niece

  outside, to be able to replace

rings subject to wear.

  There are also known

  labyrinthine chase without friction, with inverted slots that are formed by short annular slits and

  annular chambers which are arranged one behind the other

2.-

  alternating, the annular slots convert, com-

  me throttling locations, the pressure energy in

  velocity energy In the next chamber, it is

  by swirling, a conversion into heat of friction This process is repeated according to the number

of these throttling points.

  The present invention aims to achieve

  labyrinth seal at cost of construction

  as small as possible, which is maintenance-friendly

  cile and which requires no mechanical boring, nor on

the rotor, nor on the stator.

  For this purpose, the subject of the invention is a labyrinth type seal, characterized in that each pair of two rings, engaged one inside the other with clearance, one of which, outside, is mounted in the fixed bore and the other, inner, is press-fit on the shaft, alternates with a ring wedged on the shaft, or mounted to the press in the bore, and a ring

  mounted with clearance in the bore or on the shaft.

  The attached drawings represent three examples

  different embodiments of the subject of the invention.

  Figure 1 is a partial sectional view through a rotary hydraulic machine, in the area of the labyrinth seal, Figures 2 and 3 are plan views of different rings of the seal of Figure 1

  FIG. 4 is a sectional view of the base

following Figure 3,

  FIG. 5 is a sectional view of a gar-

  labyrinth seal in which all rings mounted on the press on the shaft are formed in one piece, Figure 6 is an identical view of a seal according to Figure 5 with resilient discs 3.-

  mounted to the press on the bore.

  In Figure 1 the rotor, with its shaft, is designated by the reference 1 On the shaft 10 is fixed by means of a screw 11, a cover 12 rotated with the shaft This cover 12 is made tight seal relative to the stator 13, shown schematically, at a location, not shown Between the rotary cover

  12 and the stator, is thus formed a sealed chamber 14.

  The shaft 10 passes through the stator in its bore 15 The shaft 10 is sealed relative to the bore 15 of the stator by a labyrinth seal according to the invention, designated, as a whole, by the reference 1 to the right of the stator 13, in FIG. 1, is the c Sté to be sealed A, and, on the left, in the chamber 14,

find the C8 tee B sealed.

  Of course, the piece 10 could as well be a round axis around which the rotor 13 would rotate In principle, the labyrinth seal according to the invention would not be changed, so that in

  the description which follows, this equivalent solution does not

I will not consider it.

  On the shaft 10 are mounted, in-a relatively compact block, rings 2 and 3 alternated All these rings 2 and 3 have the same inner radius r 1, such

  so that they are connected together to the press on the

  The rings 2 have an outer radius r 2 which is much smaller than the rings 3, whose outside radius r 5 is however smaller than the radius r 15 of the bore. In order to ensure a press fit between the rings 2 and 3 and the shaft 10, it is necessary that the shaft is oversized relative to the inner radius r 1 Rings 4 are arranged concentrically around-rings 2 These rings 4 have an outer radius r 4

  which is oversized relative to the radius r 15 of the

  15, so that they are engaged to the press in 4.- the bore 15 The inner radius r 3 of the rings 4 is greater than the outer radius r 2 rings 2 housed in them, so that they are provided with a certain clearance in the rings 4 With this arrangement, annular slots 20 are formed alternately between the rings 3 and the bore 15, as well as annular slots 21

between rings 2 and 4.

  All rings have, like the bag 3 in Figure 4, concentric annular grooves 32 in their side flanks These grooves 32 have a double

  On the one hand, they reduce the size of the sur-

  superimposed friction faces and, on the other hand, they form again throttling positions in the

labyrinth trim.

  FIG. 5 shows an exemplary embodiment in which all the rings set on the shaft 10 are made in one piece from a sleeve 5. The radius of this sleeve, that is to say the radius ribs 6 is identical to the outer radius r 5 of the rings 3, while the radius of the intermediate grooves 7 corresponds to the outer radius r 2 of the rings 2 The shaft

  is again oversized relative to the radius indi-

  The rings 4 are placed here between the ribs 6 and they are held by pressure

  in the bore 15, as in the example of Figure 1.

  Rings 4 (Figure 5) have a slot

  extending diametrically so that they can be

  in the grooves 7 of the sleeve 5.

  The variant according to FIG. 6 again comprises a sleeve 5 which is press-fitted on the shaft.

  The rings 4 which are engaged in pressure in the

  However, there is provided here an elastic material which additionally produces an outwardly directed radial force and which acts by means of mounting rings 8 on the elastic rings 4.

-2529988

5.-

  rings 4, various synthetic materials can be envisaged.

  as well as mixtures of synthetic material and

  The mounting rings 8 consist, preferably

  in the case of oh, between the stator 13 and the

  rotary cover 12, is formed, as in the

  gure 1, a sealed chamber 14, it is possible to

  load it by pressure through the stator, through

  of a pressure line Advantageously, we use

  read, on the sealed side B, the same means of sealing

  In any case, it is not essential for the sealing means to be in the same position as on the pipe 8 to be sealed.

same state on both sides.

  The labyrinth seal described

  has proved, in essays, as exceptionally

  tionally well, especially for pumps or

  Cryogenic plies The seal complies with

  the invention is, in general, used for all

  rotary hydraulic machines, without this em-

  Another example of use is its use for sealing a shaft or shaft through the lid of an autoclave. The essential advantages of the seal of the invention , reside inter alia in economical manufacture, simplicity of assembly, ease of exchange of elements, very low wear, simplicity of construction of the shaft and the bore,

as well as rotor and stator.

6.-

Claims (7)

REVEND I C AT IO N S   1. Labyrinth seal, no.   in particular for its use in hydraulic rotary machines, characterized in that two rings engage one into the other with play, alternate, the outer ring (4) being mounted to the press in the bore (15). ) and   the inner ring (2) being pressed to the press on the armature   bre (10), with a ring (3) pressed to the press on the shaft   (10) or in the bore (15) and engaged with clearance in the wise (15) or on the shaft (10).   2. Gasket according to the claim   1, characterized in that the lateral flanks (31) of the rings (2, 3, 4) applied against each other,   are provided with concentric grooves (32).   3 Gasket according to the claim   1, characterized in that the ring (3) which is wedged with clearance on the shaft (10) or in the bore (15) is   made of a material having a coefficient of friction   different from that of the two rings (2, 4) one in the other, with game   4. Gasket according to the claim   1, characterized in that all the rings (2, 3) which are mounted on the press on the shaft (10) are formed   by turning in one piece in a sleeve (5).   5 Packing according to the claim   1, characterized in that all the rings which are mounted to the press in the bore (15) are formed by turning in one piece in a sleeve (5) 0   6. Gasket according to the claim   4, characterized in that the rings (4) which are mounted to the press in the bore (15) are made of an elastic material and are pushed outwards. by means of spring rings (8).   7. Gasket according to the claim   1, characterized in that, from the sealed side 7- (B) of the labyrinth seal (1), between the shaft (10) and the bore (15) is formed a chamber watertight (14) which is charged with pressure by means of a pressure line, so that the pressure propagates through the gasket (1) on the side (A) to be sealed.